8 speed transmission detented shift forks

[Crazy8 55]

I am beginning the rebuild on my 8 speed transmission and I have watched Steves videos. There appears to be some sort of a steel seal in the access hole for removing / installing the spring and detent balls for the two detented shift shafts. How is this seal removed? I am reluctant to punch it out or drill it out. I thought I heard someone say that once the rebuild is complete you seal up the hole with silicone or some sort of sealant.  Also, after I removed the input shaft pulley from the input shaft, I see that the hub of the pulley was seriously wearing into the shaft seal and the boss of the case. I don't think it's an issue. There is enough material left to fully support the shaft seal. Has anyone seen this issue and did you have to do anything about it?

 

Thanks,

Crazy8

[WHX?? 49,145]

Yes there might be a welsh plug ther. Just use a small punch to knock it sideways and pull it out with needle nose. Do it after the shift rails are out. Sometimes keeps the balls from going to no mans land. 

I put a smear of silicone in there when done just to keep oil from weeping out. 

Pic would help us ascertain what's going on with the input seal. 

Word of advice on the input seal they can be tricky to install. 

Edited June 12, 2023 by WHX??

[ebinmaine 68,250]

1 hour ago, Crazy8 said:

after I removed the input shaft pulley from the input shaft, I see that the hub of the pulley was seriously wearing into the shaft seal and the boss of the case

I'd be wondering if there was a bad set screw or e-ring/c-ring or groove. 

Might have been set wrong many moons ago.  

 

[Crazy8 55]

Thanks for tip on the plug for the detent spring & balls.

 

Below are a couple pics showing the wear on the inside hub on the input shaft pulley. The pulley took the worst of the wear. I'm thinking that a brass shim washer between the pulley and the case would help prevent this wear.

 

Thoughts?

[ebinmaine 68,250]

3 minutes ago, Crazy8 said:

. I'm thinking that a brass shim washer between the pulley and the case would help prevent this wear

I can see the logic there but it shouldn't need it. 

Look around the inside belt groove for a set screw hole.  

I've had a dozen or more manual transmissions apart and never seen anything like that.   

 

 

 

[wallfish 17,078]

26 minutes ago, Crazy8 said:

Thoughts?

It almost went deep enough to just seal itself

I can see the hole in the groove in your pic about 11:00

The set screw is (or should be ) in the hub and the hole in the groove is so you can get to it with a hex tool

A tight set screw and it shouldn't move. There's no much lateral force on those pulleys

[Crazy8 55]

When I went to pull the pulley off I found the set screw to be very tight, but the hex was clean and not rounded so it came loose without excessive force with the allen wrench. The pulley was still very tight to the shaft and I had to lightly drive the input shaft out of the pulley bore. This may indicate the pulley was set too far onto the shaft. I assume that when the gear case is reassembled, there shouldn't be very much end play in this input shaft that would result in this wear. Upon reassembly I'll check the shaft for excessive end play and correct it. Then I'll set the pulley with about 1/8" clearance to the case. I think you are right Wallfish, that the pulley had sealed itself against the case!

 

Thanks for the input guys,

 

Jeff

[Achto 27,746]

20 hours ago, Crazy8 said:

I am reluctant to punch it out or drill it out. I thought I heard someone say that once the rebuild is complete you seal up the hole with silicone or some sort of sealant.

 

Most use silicone to seal the hole up. When I rebuild a transmission, I run a 5/16-18 tap in about half the depth of the hole. Then I install a 5/16 set screw to seal the hole up. 

[ineedanother 1,369]

On 6/12/2023 at 8:56 PM, Crazy8 said:

When I went to pull the pulley off I found the set screw to be very tight, but the hex was clean and not rounded so it came loose without excessive force with the allen wrench. The pulley was still very tight to the shaft and I had to lightly drive the input shaft out of the pulley bore. This may indicate the pulley was set too far onto the shaft. I assume that when the gear case is reassembled, there shouldn't be very much end play in this input shaft that would result in this wear. Upon reassembly I'll check the shaft for excessive end play and correct it. Then I'll set the pulley with about 1/8" clearance to the case. I think you are right Wallfish, that the pulley had sealed itself against the case!

 

Thanks for the input guys,

 

Jeff

Pulley placement on the input shaft should be more about the belt alignment but with the length of that belt there shouldn't be much concern.

[Crazy8 55]

I love the set screw idea Achto!

[Crazy8 55]

I came up with an idea to make some mandrels for pressing the needle bearings. From McMaster Carr I ordered short lengths of hardened & ground linear shafting and some double split shaft collars. The linear shafting is ground to very precise diameters and it fits the ID of the needle bearings perfectly. This will press them flush to the outside of the case then I'll still have to use a socket or something to set them deep enough for the shaft seals.

[Crazy8 55]

I just had another idea for these mandrels. Once I have the needle bearings pressed in flush to the case, in order to press them in the additional bit more for the oil seal, I'll slide the collars back some and slide the old bearings onto the shafts and use them to set the new bearings in a little deeper.

[ebinmaine 68,250]

6 hours ago, Crazy8 said:

I just had another idea for these mandrels. Once I have the needle bearings pressed in flush to the case, in order to press them in the additional bit more for the oil seal, I'll slide the collars back some and slide the old bearings onto the shafts and use them to set the new bearings in a little deeper.

I've done something similar to that. That will work quite well for you.