Why Did My Jeep stay in third gear?

[dinof]

Yes John, I am shifting very gently, but I always was cautious on shifting. That's what bothers me so much. And while I slept at night (barely!), when I have a vehicle that does something like this, it does bother me to no end. I can't stop that. It's been in my DNA since birth. I restored the jeep 15 years ago and I like a car to operate as just so. I love taking this jeep to car shows and sometimes, I win a class of judging which I just get a kick out of when you have classics,muscle cars, street rods, foreigns, and everything else in between. I don't do this to be arrogant or make myself feel great, I just love representing our military vehicles.

My first experience of shifting was the jeep my brother left for me back in 1976. I was 16, and the car was a 1942 MB. My fathers. My brother took that Jeep and put a V8 with a hydraulic clutch in front of T-90. Warn Overdrive, 5:38 gears. I didn't look military anymore as back then, you didn't restore a WWII jeep back to original. Roll cage, saginaw steering, Mercury 11' brakes and a '72 Ford blue color paint. The T-90 would last around 20,000 miles and that was a miracle.

After the rebuild of the trans, I didn't want to push that T-90 anymore. So, now I'm extra cautious. By the way, Have you ever drove a Model A ford? Now there's
a little bit different take on shifting skills. Makes you appreciate the chap who invented the synchro assembly doesn't it?

Take Care and wish me good luck today-
Dino F.

[Chuck Lutz]

Curious how one could change the synchro springs without tearing into the T84....since the main shaft holds 2nd gear with the 2nd blocking ring captured between it and the hub...and the hub is held onto the main shaft by a snap ring it would seem that the space between the 2nd blocking ring and the hub where the 2nd gear synchro spring is located would make it difficult to SEE the spring, let alone replace it.

I would like to know how to do this however....I can't see how to remove the entire synchro unit with the T84 still installed, with the main gear still in the clutch and the T84/T18 assembly still in the jeep. How exactly can one remove the synchro from the main shaft with the snap ring still on it and the tip of the main shaft still sitting in the 13 roller bearings in the main gear?

[gearhead]

My T-84 lost the ability to shift into 3rd gear last fall.
One of the shift plates/dogs had come partially out of the sychro and was badly bent by the sleeve moving toward the 3rd position.
I completely went through the trans at this point.
I bought some replacement synchro parts and small pats kits.
Varying quality was observed for the shift plate/dogs, I ended up using an NOS syncro assembly (had it for years before I had a G503! ).
The plates on my T-84s rebuild in the past were "wimpy" reproductions.
I have seen the same quality issues with my T-90 builds.
Just a little FYI.

Ed S

[artificer]

That's the only hunch you need to put your brains going and figure it out...

I like that....
A helpful hint is....how can you remove/replace the 3 synchro shift plates?
Someone we all know well posted pictures of how some tasks like this could be achieved, a few years back. Maybe you saved them?

[dinof]

Well I drove the jeep about 50 miles that is very stop and go. Trans was perfect. Every time I came to a stop, the shift lever slid right into neutral beautifully. Now we shall see over time if she is really good. Not once did it even seem hard, stick or whatever.

But all is not lost.....look what info on this situation came out. It's clear that there are some very skilled mechanics here and I thank you all for trying to help me. Now on top of that, we all learned many things. For starters, I know one thing......When you all buy a new synchro assembly, you need to question the supplier on what he has. A bad reproduction unit can be horrid in this case as one would have to remove the trans/transfer case. Stupid me, I forgot the definition of reproduction. I'm worried what the future will bring on what will be available. NOS can't last forever.

Thanks guys for your sharing of all this great info and knowledge. I have learned something new that I will use.

Dino F.