The slip yoke shattered today on the one two shift. It broke the tail housing (basically damaged where the seal goes). What are the chances that my transmission is also damaged?? If some pieces of the yoke got into the pan, will that hurt anything?? I only found one of the broken pieces of the yoke in the road.
I am attaching a few pictures (all from the same side - I can take more later). I will probably take the driveshaft in and have it checked out. It's a good thing that my X crossover is right underneath the driveshaft - things could have been much worse.
I talked to the builder and he said it could be fine or if it bent the output shaft, it could damage other things. Let me know what you think. Thanks.
I don't think there was any slop in the yoke. It was, however, a stock unit that has who knows how many miles and hard 1-2 shifts on it. I am attaching some pics from the other side.
Looking at the pictures, it does look like the driveshaft was too short. You can see the grease line on the trans tunnel, so that is where the zero fitting was spinning...I would definitely re-evaluate the driveshaft length.
I'd just be thankful nothing worse happened. You could always pull the trans pan and take a look for particles if they made their way there? If you have a spare similar yoke sitting around, you could see if it pushes onto your output shaft to see if it's twisted and also for slop.
I have been running the same drive shaft and slip yoke since at least 2007. I do have an old slip yoke in the shed, so I will use it to check the output shaft. I am hoping that at most it is just a little dinged and will clean up with a file. I just had this transmission rebuilt in April of 2015, so I hope it is okay.
The same thing happened to my 67 SS396, I put a set of Mickey Thompson racing slicks on my car. We were out doing burnouts trying to see the best PSI to run the tires at. My friend pulled a great no lift 1/2 shift & that was all she wrote. I took car in to local Chevy dealer to get fixed, they denied my warranty claim calling it abuse. Go figure.
I don't think that my output shaft would handle anywhere near that kind of power. My transmission is actually a THM-375, which is a Turbo 400 body with a Turbo 350 sized output shaft. They were used in full size vans. In hindsight, I probably should have just gone with a regular Turbo 400, then I would have had the bigger slip yoke. Might have avoided this whole scenario. The more I look at the picture of the output shaft, the more I am thinking it is going to have to come out and be repaired. I hate the thought of doing that in this heat. I have no shade to work in, so it will be miserable.
When you get a new slip yoke, slide it onto your output shaft, it should move freely. The chance of a bent shaft is remote, damaged splines on the other hand....
My front u-joint does not have a grease zerk - it is a Brute Force unit. As for the grease line, this car has had leaks for years (engine and transmission), so the 'grease line' is not a way to judge it.
It is possible to replace the tail shaft housing with the transmission still installed in the car. I've done it before.
In most cases I think that the larger upper flange of the output shaft and the down angle of the transmission would have prevented most of the metal pieces from getting further up into the transmission.
Yeah it's hotter than hell in most parts of the country right now which makes for some sweaty hateful work.
After looking at the output shaft closer, it is going to have to be replaced. I pulled the transmission this morning and will hopefully get it over to Hughes
Monday or Tuesday.
I'd go for the ATI version if it were me. My perception is that Inland = cheap generic stuff. Which is OK if that's all you need and your getting a much better price. Not happening here.
You might want to consider calling Denny's or some other driveshaft company and buying a complete new shaft with yoke and 1350 joints installed and balanced.
I don't know if I will have them put a larger output shaft in - I spent a lot of money last year on this car (transmission + heads). As for having a new driveshaft built, that is way more money than I can spend right now. I can't run a 1350 in the rear, because I don't think it will fit the differential yoke (it is an 8.5 out of a 72 Buick Skylark - I have to use a 3130 conversion u-joint to go from the Chevy drive shaft to the Buick yoke). If my drive shaft is not repairable, I do have another shaft in my shed that can be shortened and modified.
Once I talk to Hughes today or tomorrow, I will have a better idea of which way I want to go.
Had local company installed 1350 U Joints and SPICER Slip Yolk & Dif Yolk in 2007
on a new balanced 3.5"x.083" tubed Driveshaft in my cruzin/Racing 67 Chevelle
it is still going strong after 8+ years
To the best of my memory, a 375 was longer than any 32 spline 400 , built special length to use a one piece driveshaft in some BOP big cars. If this it true , a 32 spline output will require a longer driveshaft. Your transmission guy will give you options. While its true Spicer makes good parts , a forged slip yoke from Sonnex or Victory is a much stronger part at about 150% cost
I think that the 71-72 buick rear used a 3R type joint - not 100% sure.
If you don't want to mess with the yoke on the rear, you might want to call a driveshaft company and see if they can build you a shaft with 1330 U-joints on both ends. I believe the 1330 has the same cross dimensions and some come with a 1-1/8" cap diameter that may fit the 3R yoke on the rear.
This way you get stronger u-joints on both ends. Not quite 1350 strong, but the 1330 is an upgrade from the stock Chevelle 1310. No point in using the 1350 if you are still going to have the smaller yoke on the rear, in my opinion.
Yes , by 71 , all the bigger Buicks came with 3R u joints. And there is a conversion joint for 3R to 1330.....3R is inside lock-up so 1330 won't work in the pinion yoke. I would put a 1350 on trans end -cost will near the same - and that would put "weak link" at the rear. If its gonna break , better at the rear than the front.
3R near the same strength as 1330
I think I am going to go with a 1350 front u-joint and a 1350 to 3R conversion u-joint in the rear. I still have to wait until they disassemble my transmission to find out what the damage is - then I will decide whether or not to upgrade to the Turbo 400 output shaft.
As for breaking at the rear - I've been through that before, too. On the 1-2 shift, I suddenly lost acceleration - it was freewheeling. I had to walk back about 1/2 mile to retrieve my drive shaft from the street. The pinion had snapped off right at the differential housing. It seems the stock 8.2" setup can only handle hard 1-2 shifts so many times (to be fair, the pinion did have 188,000 miles on it).
Well, it looks like only the output shaft and tail housing were damaged. The rest of my transmission was okay. I am going to leave it as a 375-THM, as I would have to make other modifications to utilize a Turbo 400 output shaft (money is getting tight). I will get my slip yoke ordered from ATI Monday, then pick up my transmission either Monday or Tuesday. Once I have the transmission in the car, I will double check measurements, as I may have to have another drive shaft shortened (mine has a nice dent in it, so it may not be usable).
Well, I got the transmission physically installed into the vehicle only to discover that the transmission mount holes were damaged. They were only 3/8 (instead of 7/16), which was odd. When I started to put a little tension on the bolts to tighten them up, the threads pulled. So, today I went and got a heli coil kit and bumped them up to the 7/16 thread. The bolts tightened right up without any issues.
Now I am just waiting on my slip yoke to be delivered, then it is off to the drive shaft shop. I truly hope that this thing does not have to come out again for a very long time.
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