T 14 Transmission Shifting

[dixiecase]

Hello, I just purchased a 1975 Cherokee with low miles. 258 engine, t14 transmission, dana 20 transfer case.

It shifts smoothly from 1st thru 3rd gear. When you try to shift from 3rd to 2nd it grinds until you reach about 18 mph. Same way from 2nd to 1st. I am not familiar with this tranny. Is this normal or do i have a synchronizer going bad/already bad or other issues?

Thanks for time and answers.

[tgreese]

Clutch problem?

Not sure what you mean by sequencer.

What is your driving style like? This transmission is synchromesh in all forward gears, so you should be able to shift without grinding between any of the gears. That said, you hardly ever will need to shift down to 1st around town, until you are almost at a complete stop. The blocking rings do wear out after a bunch of miles. Does it help to double-clutch when you downshift? The Borg-Warner 3-speeds are not fast shifting transmissions, but they are typically easy shifters.

First post! Welcome from Boston.

[dixiecase]

Thanks, Synchronizer..... I don't drive it hard or shift gears fast. Going down an open road it will not let me shift from 3rd to 2nd without grinding until i get to about 18 mph. Not so worried about 2nd to 1st but find it odd you can't downshift from 3rd to 2nd until the speed is at 18mph or less.

Thanks

[tgreese]

Double clutch and see if that helps. If you don't know how, you can learn. https://en.wikipedia.org/wiki/Double_clutch_(technique)

I'd also suggest you adjust the clutch to make sure it's fully disengaged when the pedal is depressed. Clutch adjustment is described in the TSM.

[Tatsadasayago]

Sounds like the brass synchronizing ring or dogs may be worn out/broken.

[dixiecase]

Ok thanks but you shouldn't have to double clutch a synchronized transmission. Everything I've read says the T14 is fully synchronized in forward gears. That is why I am wondering if there is a tranny problem. Thanks for the help.

[SJTD]

I think he's suggesting it as a diagnostic, not as something that should be required.

[tgreese]

A diagnostic, or a stopgap.

Adjust the clutch too.

[dixiecase]

Ok thanks for the help

[rocklaurence]

Could be a synthetic or wrong type oil. It may not allow the synchros to drag enough to synchronnise--IDK. Its most likely worn synchros

[tgreese]

It would be a good idea to change the oil. You want this oil - https://www.amazon.com/Sta-Lube-SL24239 ... dpSrc=srch - GL-4 mineral-based oil is the right oil for these transmissions. Realize that the transfer case and transmission share oil through a slow transfer, so change and refill both with the GL-4.

The GL-4/GL-5 compatible oil you'll find at WalMart is fine for the axles, but the proper oil for the Borg-Warner 3-speeds is GL-4.

Generally it's a good idea to change all the fluids in any new-old car, when you get it.

[dixiecase]

Thanks to everyone for the help.

[dixiecase]

Do T14 transmissions usually downshift without grinding? Just trying to make it right if its wrong. If you can't downshift a T14 i can deal with it but i want it to be functioning correctly. Thanks

[tgreese]

Yes, except when worn out or broken.

That's yes to a reasonable downshift, not forced from high speeds. So you should be able to downshift into 2nd around town if you want more speed.

I've owned several Jeeps with both the T-14 and T-15. Jeep dropped the T-14 entirely in 1976, and the Wagons and trucks got the T-15 as the base transmission, regardless of engine. The main problem with the T-14 is it's not as strong as the T-15. The T-15 is up to V8 power, and the T-14 is not.

The T-14 ratios are 3.10, 1.61, and 1.0. You can use a gearing calculator to see what a reasonable downshift speed is. https://www.novak-adapt.com/knowledge/gearing/ Using the cruising RPM calculator, I calculated what the engine speed would be in second at 40 MPH for a reasonable tire size and typical axle ratio, and it's about 2600 RPM. A 40 MPH downshift into 2nd should work fine and not clash as long as you don't try to shift too fast.

[dixiecase]

That's the info I needed right there. You hit the nail on the head. Thanks. Now I know which direction to go. Thanks!!!!!

[tgreese]

NP. Glad I could help!