58 Chevy trans swap woes, driveshaft too long?

I did a search to try to resolve what I believe is a problem with my driveshaft length. I found a link to the TCI site with some good trans dimensions.

http://www.tciauto.com/Products/TechInfo/trans_dims.asp

Here is my specific problem: I bought a 58 chevy that was barely driving. After topping off the trans fluid, the car would go forward, but not backward. Checking the linkage, I discovered that the car has a Turbo-350 trans in it. Great, I think! I drive it up and down the road (forward only) and it has an awful clunking noise.

I pulled the driveshaft to check the u-joints, and discover that the driveshaft carrier bearing rubber was completely missing and the driveshaft was banging around. A mechanic friend replaced the carrier bearing (I don't have a big press) and I replaced all the all u-joints.

In attempting to replace the driveshaft in the car, it seems like it's too long. I can't get the driveshaft pushed forward enough to get the rear u-joint into the differential yoke. As you know, the X-frame design of this car makes driveshaft removal and replacement a cross between a Chinese puzzle and a wrestling match anyway. The new carrier bearing is also not lining up with the mounting holes in the frame, but that seems like a secondary problem at this point.

I suspect (but do not know for certain) that the car originally came with an iron Powerglide trans (certainly not the T350). I also believe, but can not find the information to verify, that the T350 that is now in the car is dimensionally longer than the original trans. I believe that my driveshaft is now too long to fit properly. It seems like it's about an inch too long, but this is just an estimate.

The trans crossmember seems to be in the stock location, but I am not positive of this. From what I can find, it should have had to move, or to have been modified to fit. But I don't know.

The driveshaft shows no evidence of modification. The trans cable is just sitting coiled up next to the trans case. No effort seems to have been made to finish this trans swap correctly by the PO.

Let me bottom-line this: I think some PO swapped the T350 in there for an iron PG, not noticing that the T350 was slightly longer, and just jammed the now-too-long driveshaft back in, ruining the carrier bearing, and just leaving it so.

I have done many transmission removal and reinstalls, and can do pretty heavy fab and modification work, so the actual work is not the problem. I just don't don't know where I am on this since I am not sure what was stock and what should be changed. I don't want to go off modifying stuff if I am going in the wrong direction.

Also, too make it more spooky, the carrier bearing seems to be too far forward to mount to the frame properly, although it was pressed onto where the old bearing was on the shaft. This is the opposite of what I would expect. If the new trans is too long, with the same driveshaft it should be farther back, not farther forward.

While I appreciate all opinions, I really need to get to some correct and actual information on this.

The car is somewhat inaccessible at the moment, but I can possibly get under there if need be. Sorry no pics, but that's the reason for the long description.

O mighty Hambers, what do you know?

Thanks in advance!

 

Not sure about iron glide, but th350 is the same length as aluminum glide.

350 was made as a direct bolt replacement for a glide.

 

From what I rember the carrier bearing mount holes are elongated, my 58 has had a stock 3speed, mid 70's 3 speed w/od, 700r4 and turbo 400, and the 350 and powerglide were interchangeable. Slot the holes a little more or start over with a driveline shop to measure from the trans seal to the split half of the rear yoke and get the deminsions right and I would replace the carrier with an after market alum with yellow plastic/rubber?? inland driveline sells them.

 

There's a sticky thread over at Chevytalk.com in the 58-60 section that gives correct shaft measurements for the different trans options. Seems like it says the rear sections are all the same length, and there's 3 different front lengths....I forget, go look
Don't forget to put weight on the suspension before you tighten up the carrier bearing

 

I agree with your logic about the carrier bearing should be too far back rather than too for forward.........UNLESS, by chance, your guy installing new joints put the tranny slip yoke on the wrong end of the driveshaft and you now have the driveshaft in backwards. Not do hard to do as one may think. It will still be TOO Long, but the location of the carrier bearing would be correct and you could more easily measure for correct front shaft length.

 

thanks guys. Great ideas. Couple of things:

I did nose around some other boards, including the one mentioned, but could not find the correct answer for my situation. I trust the HAMB more.

I know the DS is reassembled properly*, as I marked all the parts prior to disassembly.

What I am finding is the front yoke is hard up against the trans case, there is not enough room for the diff u-joint to get into the diff yoke (as if the DS is too long), and the carrier bearing is too far forward (unbolted).

*how about this: The rear yoke of the front shaft presses off so the carrier bearing can be pressed on the front shaft. There is about another 1/2" amount remaining that yoke can be pressed on before it is flush (wish I had a pic here). It was not flush before. As it is it seems 1/4" short of where it was before (I knew I should have measured that). This would make the shaft 1/4" longer now.

Anybody know if this back yoke on the front shaft needs to be pressed "all the way home"?

PS I tried the DS install both with the rear axle hanging, and supported.

 

It is not that I am hard headed........BUT....is it possible the PO assembled the driveshaft incorrectly (reversed front to rear) and that even though you marked everything to assure reassembly as it was when you found it, the thing was wrong from the start. SOMETHING has to account for the carrier bearing being in the wrong location. The length of either shaft would influence that location but WHICH shaft would determine whether it is forward of, behind or in the right place. I think you have two problems. Sort out the carrier bearing location first and the rest should follow.

One other thought, is it possible the whole driveshaft assembly is incorrect for this chassis. All the GM stuff from '58 thru '64 used this design. Maybe you don't have a '58 Chevy shaft to begin with. Pontiac????

 

if the car is supported by the chassis, the rear axle control arms will swing the rear forward closing the distance between the trans and the rear. put the rear on jackstands and the driveshaft will fit. Paul

 

I suspect (but do not know for certain) that the car originally came with an iron Powerglide trans (certainly not the T350). I also believe, but can not find the information to verify, that the T350 that is now in the car is dimensionally longer than the original trans. I believe that my driveshaft is now too long to fit properly. It seems like it's about an inch too long, but this is just an estimate.

Here ya go

Transmission... ..Length ....To Mount...... Gear Ratios
Powerglide........ ..27 9/16” ....20 9/16” .......1.76, 1.00
Turbo 350 (Short) .27 11/16” ..20 3/16” .......2.54, 1.52, 1.00
Turbo 350 (Med) ...30 11/16” ..20 3/16” .......2.54, 1.52, 1.00
Turbo 350 (Long) ..33 11/16” ..20 3/16” .......2.54, 1.52, 1.00
Turbo 400 (Short) ..28 ½” ..... 26 ¾” ...........2.48, 1.48, 1.00
Turbo 400 (Long) ..34” ..........28” ............2.48, 1.48, 1.00
200 R4 .................27 ¾” .....26 7/8” ........2.74, 1.57, 1.00, 0.67
700R4 ..................30 ¾” .....22 3/8”......... 3.06, 1.62, 1.00, 0.70
4L60E .................30 ¾” ......22 3/8” ...........3.06, 1.62, 1.00, 0.70
4L80E .................31 9/16” ...30 11/16” .......2.48, 1.48, 1.00, 0.75
C-4 ....................30 ½” ......20 ¼” .............2.46, 1.46, 1.00
C-6 ....................33 ½” .......22 ½” ...........2.45, 1.46, 1.00
AOD/AODE ...........30 ¾” .......22 ¼” ...........2.40, 1.46, 1.00, 0.67
4R70W ................30 ¾” .......22 ¼”............2.84, 1.55, 1.00, 0.70
E4OD/4R100 .........37 3/8” .....29 ½” ...........2.71, 1.54, 1.00, 0.71
Torqueflight 6 (904) 29” .........22 ¼” ...........2.74, 1.54, 1.00
Torqueflight 8 (727) 34 3/8” ....23” ...............2.45, 1.45, 1.00​

46RE/46RH (A518) ...37 ½” ......24 ½”........... 2.45, 1.45, 1.00, 0.69

 

Good call.........cool reaction and the KISS method....keep it simple..

 

i believe that maybe the cast iron powerglides were a bit shorter than the aluminum ones?

i do know that some of the early aluminum case ones are a bit shorter , i did not know that until i was showed the difference at a tranny shop

 

just did a search and found this thread :

http://www.jalopyjournal.com/forum/showthread.php?t=214282

 

Thanks guys. See, I also believe the iron PG's are shorter than aluminum PG's, but I don't know for sure (and if so, by how much).

Perhaps I believe this since it conveniently fits the symptoms I have found, so I am merely believing a cause that fits the outcome!

I stopped by my guy that pressed on the bearing, and he believes that all 3; iron PG, alum PG, and T350 are all different lengths, but again, is unsure of what and how much. He says he marked and measured everything to replicate it.

No, I cannot verify that the DS is the stock, or correct, one either. I mean, it's close, but not right.

I have one idea I might try, but I want to leave this up for the night crew, and hopefully I will get more info.

I am still waiting for that one guy that will post up and say: "I HAVE ABSOLUTE EXPERIENCE WITH THIS AND KNOW FOR A FACT THAT...etc, etc."

I know you're out there brother. Thanks, JK

36-3: Thanks, I did find that thread. It is also informative, but not definitive. But thanks.

 

mine has a sbc and a th350, i thouth the same about the carrier being in the wrong place, but when the weights back on the car it pulls to the right position. you may have to shorten the front section 1.5in, as im pretty sure the 350 and the powerglide are 1.5in diff. the x frame used a shorter tail powerglide specific to that application..... from what ive been told....

 

not the same but relative,i guess.my 59 had a stock little bitty 3 speed stick in it.when i went to a saginaw 4 speed i had to shorten the driveshft.forgot how much been a while. i'm sure the turbo is longer than the p.g. you might as well plan on having that front shaft shortened. and i've never had to press the carrier bearing on/off.slips rite on,off with a light tap. i know this dosen't help a lot. there is also a site called x-frame .com that might be of some help.good luck.bruce

 

that hanger bearing is not a good deal as the rubber is set for failure due to the shaft walking back and forth, they had the same set up on some pickups later and they sure spit out a lot of hanger bearings
not a good set up
well its time to get the driveshaft cut and if you miss , speedway motors makes longer drive yokes which can be handy for wrong length driveshafts
it unfortunately is no longer $15 to get a driveshaft cut, and the junkyards dont have much to pick from either

 

http://www.tciauto.com/Products/TechInfo/trans_dims.asp

good info^^^^

 

i've posted this before, take the carrier bearing and fill the slots on it with silicone.pack it full.then tape it up and let it set up. old drag racer showed me this trick.pretty mush makes it a solid rubber(sorta) mount

 

B.A., I like the tip, perhaps I will try it.

What I have decided to try, is to accurately measure the geometry of the car. Trans to diff yoke, and trans to carrier bearing mounting, at least. Then square up the DS out on the floor, and accurately measure that out. I am confident that comparing the measurements will point to the problem, and hopefully the solution will be clear.

The more I have been thinking about this, the more angry I am at Chevrolet engineering: All of the movement in this driveshaft will be in the rear section, due to the rear suspension. From the carrier bearing to the trans could be hard mounted. Yet chevy uses the familiar slip yoke at the trans output, probably because of "parts bin engineering", where it's not needed.

It's the rear part that needs the slip yoke, like a Suburban or big truck has. Instead, I suppose the carrier bearing rubber is supposed to cycle back and forth to absorb the length change. Even if it's only 1/4", this is not the correct way to do it!

And I'm the one that gets laid off after 25 years of mechanical engineering (?)

 

I think you have correctly assessed the situation......especially 're where movement is 'absorbed'....hence, may not be a good idea to 'solidify' the carrier bearing rubber mount...........just a thought

Ray

 

the driveshaft not only moves up and down with the suspension, but in and out of the trans too. the movement isnt only in the rear. thats why the carrier has the rubber bushing, and theres a slipyoke in the trans. now, if you hardmount the carrier you must use a lowrider style rear section(slipjoint), but those cost about 300 bucks just for the rear section. they make kits for this on lowrider sites. that would isolate the movement to the rear only. however you do your measuring, do it with the weight on the suspension, on jackstacks under the axle, ect, like was previously mentioned. im sure all your car needs is to have the front section cut down a bit.....

 

HD shaft section
http://www.lategreatchevy.com/product.asp?pf%5Fid=521018&dept%5Fid=1866

HD carrier
http://www.lategreatchevy.com/product.asp?pf_id=521226&dept_id=1866

kit
http://www.lategreatchevy.com/product.asp?pf_id=521168&dept_id=1866

 

I don’t think anyone has mentioned this yet: If your ’58 Chevy was originally equipped with a 348 engine then it may have also had the three-speed Turboglide automatic transmission, which could account for unexpected dimensions.

 

Right Skunx, this is what I was talking about, this would be superior:

http://www.lategreatchevy.com/product.asp?pf%5Fid=521168&dept%5Fid=1866

Of course at $450 it should be.

I will try to troubleshoot what I have, mostly since I already have it, and it was in the car.

My mechanic also has an iron PG in his '63 (* see post below) wagon. We're gonna put it up on a lift and get an accurate measurement of that.

Whenever I have trouble with something and can't find an expert, I want to become the expert in that area. I will get to the bottom of this.

Thanks for the interest guys.

 

cool, good luck. after going thru all the measuring, looking for parts to re-configure the setup, or redo what chevy did, i just ended up using what i had, it fit fine when i had the car sitting at rest with the weight on it. but i will add that a friend who has multiple 58s, has a few parts piles, and we checked the driveshafts he had. they all came up different. i think all the rear sections were the same, but the fronts were different. you may just have the wrong year shaft. mine is only about 17'', i think. cant really measure it for you now, as its installed.....

 

turboglide was a 2 spd like powerglide. only 3 spd. was manual. turbo 350's had 3 different lengths, all in the tailshafts as main cases were the same. most people mistook the Gr on the column indicator as low gear and burned up their transmissions. Gr stood for "grade retard" and acted like a towing brake for steep inclines like mountain side while towing trailer. the guys over at chevytalk are pretty sharp. driveshaft was shit design right from the start. post some pic's of your project as it sounds cool.

 

Unless your buddies wagon is a '62 model or retrofitted with '62 or earlier trans, it will be an aluminum case powerglide. In '62 Chev supplied the 327's & 409's with alum case glides and 6 cyl 235's and V8 283's got cast iron glides. In '63 Chev got the new light weight 6's (230 in std cars) and that and all V8's came with aluminum glides.
Ray

 

*Oh jeez, Hn you're right. My friend's wagon is indeed a '61, not a '63. Don't know what I was thinking.

Skunx, not much makes me actually chuckle. But to hear that all of your friend's '58 driveshafts measured out differently certainly made me laugh! So much for finding a nice stack of stock 'shafts for comparison purposes. What, were '58 chevies driveshafts all individually hand-fitted? Oh boy.

Seems like the more infomation that's offered, the more variables get introduced, instead of narrowed down. Not really the outcome that I was hoping for! For a simple part non-fit, this did get a whole lot more interesting quickly.

 

Hi John, Im Bill from Kingston and I am going to convert my '59 impala from the cast iron glide to a short 6" tailshaft th350. It looks like the 350 is about 2 inches longer than the cast glide so the front driveshaft will have to shortened. Im going to put them side by side against the wall and measure them exactly. Im hoping the mount will work or at least moving the mount to the second set of holes for it. It looks like it can be mounted in two places. Will let you know what I find out.

 

Update. I found a driveshaft on craigslist in poughkeepsie and as luck would have it it is about 2 inches shorter than my original. Should be correct for the th350.