Inliners International Forums General Discussion Drive Train T5 into a stock 1947 aerosedan

Not many responses or visits either I think but I will ask. I have been doing a little research on Stovebolts and a few links shared here and there. My plan is to replace my stock 216 motor with a 1958 235 which I will have rebuilt or at least refreshed. I have located two different T5's one in a Mustang the other in a S 10. Unsure but I think both are pre 88's. On Stovebolts it was suggested to use S 10 if you want to keep bench seat. Was wondering about gear ratio's which I don't know Jack about, it was said to make sure my differential would be a good match. I have no idea what a stock 47 had. It was also said the T5 would bolt up to my stock bell housing. I read where different T5's had different output shaft splines. I would really like it if I could buy this whole S 10 and everything swap perfectly. So I guess I'm just asking what others have had to do to make a swap like or similar to this. Would my stock diff ratio be stamled on it? or maybe a tag? What about using my stock driveshaft and diff ?

Welcome to forums Mike. Mating the T5 to a Stovebolt has been discussed at length here and elsewhere. There is an old Inliners technical article about which variant to choose and why: Jack Halton - John Martin circa '08.

The S10 variants mate up to the Stovebolt bell house by virtue of a common bolt pattern. But other variants can be adapted.

From the transmission tail back there is nothing compatible with the enclosed (torque tube) drive line used through '54.

When going to a T5 you will have to convert to an open drive line. If you want to preserve most of the stock rear-end components you can try to source a '55 to '59 third member. The 'pumpkins' from them will bolt up to the banjo in your '47 and allow you to use ring and pinion ratios from the same era with your axles.

Your rear-end banjo will need to have its spring perches reworked for open drive line use. The stock perches are designed to rotate/pivot up and down as the 3rd member moves through suspension travel. Open drive line spring perches are welded fast to the banjo in order to set pinion angle - which is directly related to the installed angle of the new T5 tail shaft.

Good luck with your swap.

regards,
stock49

Most '47 era cars came with a 4.11 rear end - though there was a 3.73 option. There are no external markings on a pumpkin to indicate installed ratios (like the later metal discs).

Direct inspection is the best approach. 4.11 pinion's are marked with gear count 9-37; 3.73's gear count 11-41. In '50 the Power Glide was introduced with a 3.55 - gear count 11-39. All are marked with month & year of manufacture.

Thank you for the reply and the info. The list of what ratio came in what vehicle will be helpful looking for a donor. I did go to Stovebolt's Tech tips and looked at let Tom grade your driveline and that suggest a 3.76 1st gear with the .73 OD. From the list of ratio's you supplied there are about four different S 10' that came with that ratio. Also a couple Astro Vans although I don't know if the shifter position would be correct for the bench seat in my 47.

In looking at the list of T5's I see that some years and motors the same have different ratios. There is a factory part # that is different between years, engines and ratios. Do you know if you can tell which is which without having to remove the trans?

I put a couple of T5s in my 40 chevy coupe years ago. It is a major undertaking. First attempt was with an s-10 but ended up with a non-world class out of v8. I had the body off so it was easier work on the changes.

One thing that seems to be missed is lack of room between the floor and the cross member. The T5s are much deeper and longer than your current trans.

I ended up cutting out the mid section of the cross member but saving the triangular ends that hold the bake and clutch and add strength to both frame rails. When the piece was removed the two triangular structures rotated or sagged down. A new cross member section was made to bring triangular ends and frame rails back to their original position and to go behind the longer T-5. It is made from 1 1/2' angle iron shaped like V with two straight ends extending out from each end of the V - kind of a flying V shape. I bolt it to one side and jack it up into position and and bolt up the other side so the rails and triangular ends are back at their original position.

Radar, you mentioned putting a couple T5's in, after you modified the cross member the second probably wasn't much trouble huh? I'm not quite sure if the crossmember is very different in a 47 vs 40. Did you put the second in to change gearing? What I read was putting them in trucks and gear ratio selection although it will be connecting to a 235. I'm thinking first choice ratio is 3.76 first and .72 OD, second choice 4.03 first and .76 OD. That pretty much limits me to a 1985 or 86 if I want to keep mechanical speedo.

Mike - Yes the second one was easier. Had to change the clutch plate and throw out bearing and transfer the S10 rear section to the new one.

I changed due to the very low 1st gear of the S10 - the old one it was 4.03. New one is around 3.0. OD changed from .76 to .63. Mush better takeoff and smoother shifting.

Don't think there is much difference in clearance between 40 and 47 cars.

You should go measure one before you start. I tried to measure where mine sits in the car/frame. The old cross member sits right behind the seam between the front and rear castings. I cut off a boss that hangs down about 1.5" on the rear casting which was not needed. So the bottom of my T5 to the top is about 11" where the old cross member sits. And the bottom of the T5 sits right where the bottom of the old cross member was. In other words, the T5 hangs down in the space where the old cross member center section use to be.

I hope you probably realize this change will require major surgery to your car. You might want just try to put an overdrive unit behind your existing trans.

Yea I don't want to get into altering from original too much. I was hoping to bolt up maybe change cross member and install open driveshaft and rear end. But I can imagine it'll be a can of worms. Definitely need to do more research. Thanks

Well I thought I found the right T5, driveshaft and rear end for a pretty fair price and it has a 145 part# tag which is supposed to be out of a 85-86 S10 and with the 3.76-1 first gear and .72 OD.ratio. That is per the list anyway. Well the tail shaft housing is date coded 88 and the forward half has a 91 date code. I checked the ratio by marking input and out put shafts at 12:00 and turning output CCW 10 revolutions and counting input shaft spins. Did that for first and OD and it seems this trans has the 4.03 first and .86 OD, not what the part number on chart suggested it would be. But still it is a matched trans and rear end from same S10. The tag sold me, I thought luck had found me with the right ratio I was looking for. The rear end has no tag telling ratio I guess I could spin and count revolutions. Could 1st and OD gears be changed?