Jump to content

1938 Special Gearbox!


Guest Grant Magrath

Recommended Posts

Guest Grant Magrath

Time to sell the Model 41, and before we do, it might pay to sort the gearbox. Grinds through all the gears. I'm no expert when it comes to gearboxes. Suggestions?

Thanks!

Grant

Link to comment
Share on other sites

It sounds like you are speed shifting and/or the synchronizing gears in your transmission are not working properly.

Because pre-31 Buicks do not have synchromesh transmissions, I just use 240 WT gear lube to slow down the higher speed gears between shifts. By taking your time between shifts, you allow the gears to match up before shifting (double clutching takes up more time too). I use the same lube in my 31 Buick, but have not yet needed to change the lube in my 38.

My two cents...

Link to comment
Share on other sites

5 or more years ago someone from Lincoln offered me a 38 gbox/ transmission. Will try to see if I still have his details.

Does the 38 future sale mean the 39 in fully on the road ?

Link to comment
Share on other sites

Guest Grant Magrath

Almost Allan!

The plan is to make room and free up some money for a ski boat for summer. My sister and brother in law are building a place in Akaroa, so should be fun!

Wireon, windlace and headlining arrived from HAmpton Coach today! Need some more soundproofing tiles before we move on.

You know, I'm pretty sure Horopito Motors had a 38 gearbox when I was there in 02.

Cheers

Grant

Link to comment
Share on other sites

I am not sure if this advice will apply to the older gearboxes (my '38 shifts ok), but on newer transmissions, I have now found two examples where the viscosity was too high. It seems that the synchros require a controlled flow of oil out of the synchro cone area when the engagement begins (note the grooves between the segments on your synchros). A lube that is too viscous will be slow to leave this critical interface, and the synchro will have a hard time bringing the gear up to (or down to) the correct speed.

My son and I put a new seal in his transmission, then refilled his high mileage pickup with a very thick oil, thinking that was the right thing to do. Shifting was much worse, at least until things warmed up. The parts guy looked up the correct gear oil, and it was a much less viscous blend (called Pennzoil Synchromesh, I believe). Switching to this lube made the high mileage S-10 shift like new.

The other example was designed to run with ATF (late seventies Dodge).

So, you may want to try the factory recommendation first, then go thicker if not satisfied.

Jeff

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...