3 Speed T-Case to 4 Speed Transmission ? (1 Viewer)

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Steamer

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I’m just now starting this conversion and I couldn’t find an answer by searching, so here is my question.

I have already got the transition input gear, bearing & seal from Cruiser Teq. I just opened the 3spd T-case and the input gear along with a PTO gear came right out.
Am I right to assume that the PTO gear from the 3spd T-case does not get used and I’ll replace it with which ever is in the 4spd T-case meaning the PTO gear or spacer?

T-Case Gears.jpeg
 
I believe you are correct.
 
Yes. Use the spacer out of your 4 speed case in place of the pto gear. Make sure you get all the pieces on the trans output shaft
 
I’m just now starting this conversion and I couldn’t find an answer by searching, so here is my question.

I have already got the transition input gear, bearing & seal from Cruiser Teq. I just opened the 3spd T-case and the input gear along with a PTO gear came right out.
Am I right to assume that the PTO gear from the 3spd T-case does not get used and I’ll replace it with which ever is in the 4spd T-case meaning the PTO gear or spacer?

View attachment 3290076
FYI, @orangefj45 sells the spacers that have been properly hardened if you need them....
 
Yes. Use the spacer out of your 4 speed case in place of the pto gear
Got it! Looks like the 4 speed has the PTO gear also.

FYI, @orangefj45 sells the spacers that have been properly hardened if you need them....
Guess I'll use the 4spd gear or would there be a benefit to getting & using the spacer?
I know I'll never utilize the PTO.

4spdTcase.jpeg
 
The gear should work fine. Pay close attention to any washers that may be in there.
 
The gear works perfect. No need to replace it. Just make sure that the spacers between the back of the trans and input gear and between the rear Tcase bearing and washer/nut at the end of the shaft are in good shape.

We offer/stock/sell all the parts for the conversion.

Happy to help.

Georg @ Valley Hybrids @ Cruiser Brothers
Shop 209-475-8808
Sales@valleyhybrids.com
 
Got the 4 speeds onto a better working surface in preparation for the separation. Getting the spacer off took some persuasion and that output bearing was fighting all the way to the end.
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Well, This is not good.
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I think my next move is to dig out another H42 & T-case combo that I acquired years ago from a 75 40. It is buried quit deep in the shop and should take a half day getting it out and onto the bench. I have no idea of its condition but I guess it’s time to find out.
 
Worn output shaft splines are super common, but typically only on the 16-spline units ( like this one ) and the 19-spline version in the automatics.
You’ll also see considerable spline wear in the input gear.

We see this often ….. we have replacement main shafts and matching input gears in stock. Happy to help if you need them or anything else for your rebuild.

Georg @ Valley Hybrids @ Cruiser Brothers
Shop 209-475-8808
Sales@valleyhybrids.com
 
Worn output shaft splines are super common, but typically only on the 16-spline units ( like this one ) and the 19-spline version in the automatics.
You’ll also see considerable spline wear in the input gear.

We see this often ….. we have replacement main shafts and matching input gears in stock. Happy to help if you need them or anything else for your rebuild.

I cringe at getting into a rebuild, at this time anyway. I gotta have look at the spare pair I’m just about to start digging out, see what we’ve got, and go from there. Thanks for the info Georg.
 
If you know for a fact that your “spare” trans worked well and shifted fine, at the very least I would replace the input seal and all gaskets as well as update the drain and fill plugs to the 10mm allen style version.

If you crack the top open, inspect the synchro ring clearance. That’ll tell you lots about the transmission.


And of course we have all that “stuff” in stock as well.

Georg @ Valley Hybrids @ Cruiser Brothers
 
If you crack the top open, inspect the synchro ring clearance. That’ll tell you lots about the transmission.
Im about to crack open a 4 speed myself. Is there a good resource on here for inspecting them to decide how deep to go into it (and to determine if I need the seal kit or do an entire rebuild)?
 
If you pull the shifter top you can visually inspect it and check the synchros. I went a step further and spun my input shaft with a big mixing drill and shifted through all the gears too in order to listen for noises, etc. Mine was an unknown to me 4 speed.
 
Took a while but cleared a path to it.

75Pair.jpeg
 
If you pull the shifter top you can visually inspect it and check the synchros. I went a step further and spun my input shaft with a big mixing drill and shifted through all the gears too in order to listen for noises, etc. Mine was an unknown to me 4 speed.
Exactly!
Also, pull the drain plug snd look for metal particles on the magnet.
Pull the front bearing retainer and rear core plate. See if you find any metal particles there.
If everything is clean and the synchros check out, I’d say re-seal the trans and run it.

Hope that helps.

Georg @ Valley Hybrids @ Cruiser Brothers
 
Exactly!
Also, pull the drain plug snd look for metal particles on the magnet.
Pull the front bearing retainer and rear core plate. See if you find any metal particles there.
If everything is clean and the synchros check out, I’d say re-seal the trans and run it.

Hope that helps.

Georg @ Valley Hybrids @ Cruiser Brothers
I know you can't give away all the secrets, but what is your oil of choice? Any value in going with high dollar stuff? I know the oil needs to be compatible with brass, just curious if anyone has found any advantage to using say a Redline shock proof, or other high performance gear case oil.
 
Got most of the crud off, which was plenty, and popped the top. It’s looking cleaner than the first one and no rust. Maybe a few nicks on a few gears but seems to rotate smoothly and was shifting good before opening. I don't know how to evaluate synchronizers. I’ll drain the oil when I can get it elevated. No engine crane so I’m dragging it around. Ran a magnet all around in the bottom and under the gears and picked up nothing. Tomorrow I’ll separate and get the dope on the output shaft.

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The FSM has the synchro measurement info. Dial calipers and you’ll know if they are good enough. Can post pics of the FSM tomorrow if you don’t have it. (Not just a pic of the cover either, but the actual info!)
 

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