No joke - Yoke won't slide into the transmission

[Red Regal T]

on my El Camino turbo 6 hybrid. The 86 Camino came with a fuel injected 4.3 and a th200r4. I changed out the original 200 and installed a BRF model. This particular trans I installed, I never used before nor do I know anything about it other than it is a BRF and changed out the 7.5 with an 8.5 rear, necessitating, so I was told, the shortening of the driveshaft. I got to the point in the build where I had to measure how much I had to have removed from the driveshaft. Now, here's the rub ... when I went to install the original Camino driveshaft the yoke would only go in about a third of the way. It also looked as though I might not have to cut it, so I took a hammer and knocked the well lubricated DS onto the transmission splines and I could turn it by hand. As it turned out, the yoke went all the way in to the shoulder of the yoke when fully installed, so I knew I had to remove it for shortening. My question is any ideas why I would be having this problem with the yoke not sliding in place on the transmission splines? Is there different thicknesses of the brass bushing inside the rear of the housing? There didn't appear to be any damage or tell-tale clues on the splines after I removed it. TIA

 

[Nick Micale]

You might want to check the splines on both the yoke and the output shaft to see if they are straight?

We have seen them twist and make it hard, if not impossible, to slide together.

 

[Pronto]

The splines on the shaft and in the yoke fit pretty tight. If you put grease on the yoke it might have made an airlock preventing you from just sliding it in. Maybe a light coating would work better. I know when I did my U joints the yoke had to line up just right for it to slide in. Remember to leave enough of the yoke out of the trans so it will have room to move in and out. There's probably a wear mark where the seal has been riding. That might be a good guide.

 

[Red Regal T]

Well, I know there was no problem removing the Camino driveshaft from the original transmission, so I don't think the DS is the problem, and like I said, I don't know anything about the BRF I'm using. So, if there is any spline damage, which I think is a good possibility, it would have to be on the output shaft of the transmission. After I get the DS shortened, I'm just going to install it and go from there. I was somewhat concerned I would have big time problems getting it back off, but while it was somewhat of a PIA, I got it off after a few minutes of prying and hammering with a drift, so therefore, I can repeat. I'll just do some burnouts in reverse to straighten it out.

I put the grease on after my first attempt to slide the yoke in, so there was already a problem, Pronto. Thanks, guys.

 

[Otto J]

If the BRF is fresh with a new output shaft bushing, the bushing may be messed up from installer

 

[pacecarta]

if it only went 1/3 i doubt its splines in the yoke

but have seen quite a few that wouldnt move forward enough to drop the ujoints out of the rear pinion yoke

twisted splines in the yoke will look like this

 

[Red Regal T]

Thanks for your input guys. This trans is not fresh by any stretch. I bought this trans used with some other parts locally probably 6-7-8 years ago from a TR guy who told me he also bought it used but had never used it. In fact, it had a broken ear on the trans mount, and I got it pretty cheap at the time. I got the ear welded and figured I'd try it out on this project. At least this way, I'll see if it is any good at all or just a core. The alternative was to have another one of my cores re-done. Possibly the broken ear, which included one of the bolt holes, is a tell-tale sign of other damage, but if it shifts, it will do the job at least temporarily.