Inliners International Forums General Discussion Drive Train 1985 Chev Overdrive Trans

I know this topic has been discussed but I couldn't find anything on it. Just a quick over view on what you guys think of the Aluminum cased New Process 4 speed (3 plus O/D) trans that was used from about 1981-1986 Chev Pick-Up and Vans. I am told they will bolt right in where a 4 speed is and they work real well. Biggest advantage is the shifter would stay in the same place and I don't have to touch the clutch or bearing. About $400. up this way. Don't know how that compares with other parts of the country. Thanks Guys

Good topic Don! I'd like to add to your request for anyone who is familiar with them to also include the gear ratios for those trannys.

Great topic. I own two of these and I think they are great.

Gear ratios are very similar to those of the 700R4 -
1st - 3.09
2nd - 1.67
3rd - 1.00
4th - 0.73

This is really the only reasonably priced, bolt-in alternative manual overdrive transmission to the T5. There are other choices, sure (NV3500, NV4500, etc). And there are add-on Gear vendor units. But you're talking more mods and more $$$.

This transmission will fit directly in place of a 1966 truck 3 speed transmission - that's what I have - with no driveshaft mods. You don't even have to change the speedo cable. These will fit the standard smallblock bellhousing (which is the same pattern for the later 6s).

There's also a HUGE difference in cruising speed with the OD. I went from straining to maintain 65 to cruising at 80 (2600 rpms). It feels really good to finally have the left lane traffic hurrying over to get out of your way for a change. :rolleyes: But you get used to it ............ I lied, you really DON'T!

The one I currently run I bought off Ebay completely disassembled, had it fully rebuilt, and am still out of less than $400. The second one I got for about half that. They're fairly hard to find so I recommend that you snag one if you find it at a decent price. Replacement parts and rebuild kits are readily available.

-magic mike-

I have one in a 51 Chevy PU, great.Beware there are two models, the more common one has a funky Mopar bolt pattern, uses a factory modified clutch housing. The other model is typical Chevy bolt pattern,takes a 1-1/8 10 spline Chevy clutch disc and the out put spline is the Saginaw style. Like all Chevy car manual trannies, it's 21 inches long.The front bearing retainer is slightly larger than the car trannies or some trucks. I truned down the retainer to fit the 51 pu clutch housing which has the same sized hole as Chevy cars.

Thanks guys. I have located one at a Recycling yard and am going to check it out in the morning. Hopefully it is what I want...

Hey GM Dad . . .

The borg-warner 4 is a nice unit.

I had an '86 half ton with one these behind a v-thingy. I bought it new around Christmas time in '86. Got it for a song as the new body style was out for '87 and the lots were full of the old style trucks. As I recall that was the last year for a carb. Had some funky air pump for emissions as well.

The only problem I had was the clutch went at 35,000. Tranny place said that the factory used some kinda aluminum bushings on the throw out -- which of course didn't last. They put in new clutch with aftermarket steel bushings. I got another 120,000 out of that with no other problems. Truck still ran great -- but 10 Cleveland winters with all that salt didn't leave much sheet metal -- had to sell.

The v-thingy with a stick was a hoot. 3.73 rear end made for smokey burn outs in 1st, but a nice cruise in 4th. Oops forget this is the inliners board

stock49

Stock49, your truck had a floor shift in it then, correct? I don't see how they could use this trans any other way. Will make it easier when I go to check it out.
Thanks..Don

Yeah . . . the shifter came right out of the tranny. I replaced the stock shifter ball with a Hurst T-Handle from Summit Racing. Man I loved that truck!

Here you go.

http://67-72chevytrucks.com/vboard/showthread.php3?t=111715&highlight=process

http://www.motivegear.com/tech_info/tranny_guide/tranny_guide.html

I may have to see if I can find one of these trannies instead of rebuilding the T-5 and having to fab everything up. Good luck. john

Thanks for the tech link. A lot of good info there. I am going to try and check this one out today if it ever stops raining....

Here's a pic of the one I'm running behind a mildly built 292.

http://bellsouthpwp.net/w/f/wftyler/NP_sidecover.jpg

Mike, that is the aluminum case one with the Chevy bolt pattern, correct? Works good for you? How do you find the shift from 1st to 2nd (3.09 to 1.67) Is it kinda steep? What gars you running? I checked mine out yesterday and they had it marked wrong, it was a 4 spd top loader with the bull low first gear. Have to keep looking.....

Yes this tranmission has the typical Chevy/GM bolt pattern. It bolts right up to the old heavy duty cast iron GM truck bellhousing, even though the bellhousing from the factory was aluminum.

I have a 3.73 geared rear end and I notice little difference with the 3.09 first gear of the New Process vs. the 2.85 first of the old 3 speed. My engine is larger than I had with the old trans and the cam is stronger so it may be that I can just rev out first gear further with the engine mods.

I almost was tricked into a Granny 4 speed at a salvage yard in Alabama a couple of years ago when I was looking for one of these. Fortunately Tony P had already posted a picture of his at the Stovebolt website so I knew what to look for. I also knew that none of the New Process tranmissions had a top-loaded shifter. The New process will also have a 10 bolt side cover. Most salvage yard guys probably don't even know these tranmissions ever existed so you can't count on them to know what to look for. If you're fortunate you'll be able to snag one of these for an 4 cyl S-10 T5 price.

-magic mike-

hello...Long time....Thought i would comment on this Trans...Glad Magic Mike has been able to help others....I was introduced to this trans years ago and then introduced this trans to him and many others years ago on the Clifford Forum and then mentioned it here many times also...I have been using this trans since 1998 ( I have 4 of them and 2 of the special bolt bell housings also)in my 1971 292 C20- at that time many had not heard of it and were quite surprised to find out GM adapted this trans from Mopar -see this trans is the base New Process 833 that Mopar used as their 4 speed in all their 4 speed applications in the 60's and 70's-there were bascically 3 versions..1st was the "light" duty as i will call it-I do not know the Mopar "code" for this 1, then there was anther version( again I do not know this Mopar "code" either)It was as Many racers know is the STRONGEST Perfromance 4 speed ever made-ask around-this 833 was used on the Hemi muscle cars...next was the 833 version that this GM version derived ....Mopar started using these trans in vans and light cars and made the trans a 3 speed with overdrive- the ratios were spaced further apart and 4th became a .73 overdrive....As far as how this trans body was cast/made, it does incorporate 2 bolt patterns-1 the standard Chevy 3/4 speed and also 1 bell that has the Mopar bolt pattern on the drivers side and GM pattern on the passenger side-this bolt pattern can be a challenge(the side cover is so close to the hole you will have to use your own mechanical skills to install a bolt--you just would not believe this until you see it--some of these trans on ebay with this bolt pattern have this bolt still attached......And yes this trans is a DIRECT BOLT-IN trans for your GM engines-Inline 6, V-6 and V-8....I recommend buying a bearing kit and replacing the 2 main bearings and needle bearings-this kit is approximately $110.00 ( with shipping)....There is a shifter made especially for these trans or you can buy 1 from Hurst-again it would be for the 833 trans....hope this helps.....with this trans and work i have done with my 292 powered 5000 lb C20 , I can get 22 MPG at 70 MPH....10-16 around town...this trans is a great alternative to the more expensive and involved T-5 conversion....you may consider using the money saved to install the PES Bolt-In Lumps-the Chevy Inline 6 head is so poorly designed you can never get good mileage until you at least install the PES Bolt-Ins--- even if you only use stock valves......hope this info can help you....

Lee, good to hear from you again. Thanks for filling in a piece of auto-trivia for me. I knew about the Chevy 4 speed and I knew about the Mopar A-833, but didn't know they were effectively one and the same.

In fact, I remember reading a magazine article a number of years ago on how to adapt the A-833 for use with Chevys.

I haven't been active on the boards since about the time Clifford shut down theirs. But, I've been fooling around a lot more with the inline lately, so I've been participating again.

Greg

Hey guys, don't forget about the NP-540-542 transmission series. They are a close ratio 4 speed w/ a granny gear, much more useful than an SM-420, SM-465, NP-435, etc, especially if you haul a load.

They came in most everything, including Ford, Studebaker, Diamond T, etc. Just 1.5 ton and larger trucks, never pickups. Obviously Chevys are the most popular. They look like an NP-435 with an aluminum top cover but have FOUR (4) shift rails-this is the only trans. w/ 4 shift rails and AL top cover. Some even came w/ OD gears (rare.)

They only came in 2WD versions, however, they are easy to adapt to 4WD. I have adapted one to a Spicer 20 transfer case (early Bronco)which I hauled loads up to 14,000 GCW behind a Buick V6 engine, and to a NP-241D (Dodge) transfer case.

Parts are readily available.

I have one in my '47 GMC(302) w/ 3.42 stock gears to get a good cruise speed.

When you look for one, don't ask for one, they won't know what you are talking about and raise the price. Just ask to get in the yard and find one and look carefully at the shift fork pins (steel) that are cast into the AL shift housing. Sometimes they get loose.

Be careful, they come in short (stock Chevy) and long input shaft varieties. You cannot always get a short input shaft for your long shaft trans. Since the short shaft varieties are getting scarce, you can put a long shaft version up against a Chevy block by getting a deep(stock) bellhousing w/ the .25" stock adapter for a GMC V6 engine and also a Chevy 366 engine. These come w/ the side crossmember mounts in the correct place.

Good luck

Have been following this form. Want to put 4spd overdrive in a 66 C-10 250 6 Cyl. 3 spd. Does anyone know if a Chevy Np 4 spd. overdrive Transmission from a 6.2 PickUp will simply bolt in? Does this have a side mount or a top loader shifter? I have read mentioned about long and short input shafts. Would this be a corse or a fine threaded shaft? The 6.2 is more than likely a diesel. Will this make a difference? Any information will be greatly appreciated.

Chopper, I am not positive but I believe the trans you are looking at is a 5 bolt mount with an extra bolt at the top. I don't know if the other 4 bolts are the conventional GM pattern but it would be worth checking out. If you had to, you could get a bellhousing from a late V-8 and it should fit on the Inline but you will lose the crossmember mount that you currently have. Good Luck

It did in mine. I have a '66 and bolted in one of these overdrive units behind a 292. Jam up fit. No mods. Even used the old 3 speed yoke. The only thing I had to do was find a "heavy duty" bellhousing (one with the 5 1/8 inch diameter opening). If you'll check out one of my earlier posts in this thread, you'll see a picture of the actual transmission I'm using. And that version of the New Process has the same bellhousing bolt pattern as any typical GM 3 speed/4 speed of the 60s & 70s.

Just know that there is at least one other variation of this transmission casting that has a Mopar-like pattern. If you get that one, then you have some work to do. First, you must get the factory bellhousing. Otherwise the transmissions' useless. And second you must use a rear crossmember because the factory bellhousing was the "circular" aluminum type (used in the 80s). You may have to remove the frame transmission crossmember for the circular bellhousing to clear. Your 1966 GM factory bellhousing has mount points cast into it to support the rear of the engine and the tranny. The circular bellhousing obviously doesn't. As you can see this begins to get quite involved if you don't find the transmission with the casting pattern like your factory box. I hope you can easily find the easy swap type like I found.

-magic mike-

Mike, I believe the trans he is talking about is the one from the 90's pick-up with a top loader shifter. Isn't the one u are using the one from the 80's with the side cover and tailshaft mount shifter? That is the trans that I am looking for...

Magic Mike, Why do you have to use the aluminum bellhousing? I had one of these in a pickup one time and I used the cast iron bellhousing with the mount ears. I didn't need to use a rear mount. Just curious. Joe

Joe,

I guess I wasn't very clear in my last post. The "heavy duty" bellhousing I'm referring to is the old cast iron type that has the crossmember mount points cast into it.

The opening of the old factory 3 speed bellhousing is too small to accomodate the larger input shaft bearing housing.

I didn't mean to imply that you had to use the aluminum bellhousing. But you WILL have to use the factory aluminum bellhousing if you have the NP tranny that has the Mopar-like casting.

-magic mike-

Now that you have people out scrounging the wrecking yards for overdrive A-833, a web page that shows what they're not looking for, is in order.

Chryslers A-833 Is a slant 6 web site, but tells the whole story.

10, 18, or 23 spline; 4.35", 4.80", or 5.125" bearing retainer; long or short tail; aluminum or cast iron.
They are all called a A-833.
The 23 spline behind a slant 6 is the same 23 spline a-833 trans in a full size Fury or a short tail 23 spline in a Dart. If any A-833 could be thought of as being weeker, it would be the overdrive version.
The overdrive gear is very small and as a result, the mainshaft journal and splined hub is smaller. Top shaft in photo.
The OD was originally designed for use in the '70s Plymouth Volarie. Don't panic. It's still more than plenty strong.

The 18 spline Hemi has straight cut gears and sounds more like a truck trans than my SM465 does in 1, 2, and 3rd.
The overdrive Chevy version has 10 splines. I'm quessing that you may not have to limit your search for aluminum cases. In the cars, they switched alum and cast iron cases and tails at will and I wouldn't be surprised if they did the same for trucks.

this trans looks like whay i.>m looking for. where does the stock shifter come out of. I have a early car 31 chev I'm putting a 235 in and I need a trans w /o.d. but the shifter needs to be in the ctr of the floor. was the stock chev shifter any good? somebody on this post said the shifter came out of the trans? yes, no .

it's true about the cases. i have two of them one is alu and the other is cast iron. they are a perfect trans to use as a cheap dependable overdrive. tom

Howdy guys been readin along on this thread and finally got the nerve to ask a silly newbie style question...Runnin a 57 chevy 3100 with the old standard 235,will this NP trans work with mine as well? Im not sure of all the sublte differnces in all the inlines yet. Ive looked into the t5 swap,but the shift location and other fab work just doesnt work for me.Well thanks for any input on and
Via Con Dios...

So my next question is, if they also come with CI cases, how do you tell an 833 from something else-i.e. Saginaw-if you come across one, and also how is the OD version marked?

Ed Pruss
Longmont, CO

the cast iron cases came out in the early 80's, gm then went to alum. i believe this trans was used in pickup/ van applications until 1987. you can identify it by it's gm 10 spline input and common small gm output same as a muncie or three speed. the case is the same length as a 3 sp. the case is round on top not like any other gm trans. the bellhousing bolts share the gm pattern on the pass side , while on the driveside only the lower bolt is the same as gm. the top bolt is in a different location. i think many of you could easily modify your bell to accept this bolt though. i have some extras of this trans to sell if anyone wants one. just drop me a line. tom

hey, tlowe, I'm interested in one of these trans> do tou have an alum one? How about the orig shifter? how much$$ thanks

32, I haven't seen very many of these, but on all I've seen they have a side shift with linkage like all the old car 3 & 4 speeds, muncie,saginaw, etc. None come up in the center as far as I know. You need an S10 5 spd. Another possibility is Ford used a similar trans in the 80's. They were a top loader 4 spd with 4th as OD. On a lot of these, they used a center shifter, although it was mounted pretty far back. You could adapt it to a Chevy bellhousing with a little work. Maybe this will help. Joe

I know of the ford trans, guys are putting jeep top shift assemblies on them, and they look like a old ford trans with the shifter out the top, is there an adapter for this to chev pattern?

That is a question for Advance Adapters.

But the reality is that you will likely pay $250 or more in a junkyard for one of these transmissions. The few times I unsuccessfully searched salvage yards in 2 states looking for one of these, one junkyard *thought* he had one and wanted $400 for it.

Another time I drove to Alabama when a salvage yard manager said his computer showed that he had one in a 1984 Chevy truck with a 6.2L diesel v8. It fit the profile for a vehicle the trans came in so I drove down. Got to the salvage yard, went to the truck and it had a top-loaded shifter. I immediately knew that the tranny was an SM465. So two long trips, a lot of calls, and no luck.

I found one on Ebay, completely disassembled, and paid a total of $105 for it, shipping and all. Got a master rebuild pack from a tranny shop and got a professional trans rebuilder to put it all together for me. The whole deal put me out of less than $400 total - parts, labor, trans, shipping, shifter and all.

The transmissions are hard enough to find as is. So unless you're in the right place at the right time, and get a once in a lifetime deal for a good trans for $50-$75, I say it's worth it to buy one from Ebay and get your project finished. Not only will the gas savings help pay for the trans in the long run, you'll also be able to cruise at higher speeds on the interstates. I can drive 70 mph all day long, turning my 292 at only 2200 rpms. Before the trans swap 70 was a painful 3300+ rpms.

I have 3 of these. The highest I ever paid for one is $160. Cheaper than most any junkyard deal you can find. Best thing is all 3 have the Chevy bolt pattern, which is the more versatile casting.

-magic mike-

P.S. This trans has 4 forward gears with 4th being overdrive. The shifter ball is set up with the forward gears designated as 1-2-3-OD. Reverse is up and to the left.

We're talking about the holes that connect the transmission and bellhousing, not the bellhousing to engine. One is the very typical, very common GM 3/4-speed stick shift bellhousing pattern and the other is a like a combination of the GM and Mopar patterns. On the passenger side it's typical GM, however on the driver's side the pattern is very Mopar-ish (not exactly, but close from my understanding). You will really need to have the bellhousing with this type pattern or the tranny's nearly useless. Then you may end up paying someone more for the bellhousing that you did the tranny. If you can find someone who will sell you one without the transmission.

-magic mike-

I have had quite a few Saginaws pass through my hands, but never heard of one like you describe.
On the MY6,other than the case,is almost identical to the Mopar 4 spd found in the Muscle cars. In fact the layshaft and bearings are interchangable.Never heard of oiling problems with those,they ar know for their durability behind big inch V-8's, but who knows.
Sometimes, the layshaft or countershaft gets loose in the aluminum case of the MY6, spits out the shaft retaining key, the shaft spins, egging out the shaft bores in the case.

Almost all overdrives were a planetary type that replaced the tailshaft of a three or four speed transmission, the mainshaft was different on most to accomodate the overdrive. This was true untill the advent of the five speeds with an overdrive fifth gear. Many of the early overdrives allowed gear splitting, ie you could have first, second, second over, third and third over.

Sam, John, and other young members are to be commended for wisdom beyond their years in seeing throught the chaos that one individual recently managed to create. It's always a pleasure to be able to pass on knowledge and experience to the next generation and obviously the group of younger people we have here have just shown us that they are well deserving of our time and efforts.

I believe the future will be in good hands.
Mike

the New process is a great choice. I'm puting one in my 59 chevy 2 door wagon, I was able to pick up the tranny at a swap meet with bell housing and shifter for $300 plus a rebuild kit for around $150. It's also listed as a New Process A833. Another option is the Ford Toploader Overdrive, for a short time GM made a bell housing that mated a ford toploader to GM motors.

I know this thread goes back a year,but I'm considering putting a New Process tranny in my '69 C-20.I found one in my area for a good price,but want to be sure I understand all that is involved.The tranny I'm considering has the funky GM/Mopar bolt pattern on front of trans case..shift rods on the side..case looks to be cast iron,20 1/2" long,10 spline input shaft (7" long from front of case).The guy who is selling it says it was mated to a '78 350 block which was installed in a '87 Chev 4WD 1/2 ton P/U. :rolleyes:
I think I have a fair understanding of what I need to do according to magic mike,which is, to definately have the factory bellhousing,and I will need a rear trans crossmember, and possibly need to remove the front trans/bell crossmember to clear the newer style "round"factory bell.The reason I bring this up is that in a reply by Tom (tlowe),he states "...bellhousing bolts share the GM pattern on pass side,while the driver['s]side only the lower bolt is the same as GM.I think you could easily modify your bell to accept this bolt...". Question: Are these two guys refering to the same pattern,or am I missing something ,and 2..has anyone done this swap that can fill me in on what I'm potentially getting into? I really like the idea of the OD, both for the lower rpm's at highway speed, and the increased fuel economy, but I don't want to end up with an oversized paperweight. Any help is appreciated.
P.S. I'm going to meet this guy on Sunday to take a better look at it...comes with a Hurst shifter AND he has the original factory bellhousing.
God Bless,

Well guys,
Here we are, Sunday afternoon,I haven't gotten any replies to my questions on 12/7(see post "1985 Chev OD trans") so.....I'm just gonna wing it and see what happens.The price is TOO good to just pass it up.Just have to re-check all the measurements I took one last time before I meet the guy that's selling this tranny(NP 435 or MY6).
God Bless,