TJ Tranny Grind...Why?

[TJ Edge]

Why would I get a very *slight* transmission grind during shifting? It's like the syncros are not aligned or the clutch is not completely engaging so that everything is spinning too fast in there to shift. I have to shift slowly to make sure everything drops in nicely.

This started happening *right* after I got some mods done. But no work on the tranny was done. That's what's stumping me...
1" Body Lift 1" Motor Mount Lift TeraFlex Belly-Up Skid TeraLow 4.0:1 Transfer Case TeraLow HD SYE & CV Driveshaft 4" Tera Long Arm Lift


I drove it around a bit with this, and then a tranny leak appeared. We had already just changed the tranny fluid. I took it to my dealer and they replaced an internal tranny seal under warranty; but they claim the rough shifting is due to the body lift changing the driveline angles. Could this be correct? I know my angles are changed; but the MM lift should have negated the effects of the body lift. That leaves the Belly-up and the Transfer Case as the potential culprits.

Could any of the above mods have screwed up my tranny just overnight?

What if I added some MM spacers to bring it up 5/8" more to angle the driveline down toward the rear more? Could stress like on the driveline cause the clutch to hang-up or the tranny to bind? The rest of the driveline is working like a clock.

TIA

[Jerry Bransford]

They're clueless if they're saying the body lift changes the driveshaft angles, it has no effect on the drivetrain or driveshaft angles. The dealer saying steep driveshaft angles could be causing the grinding is a new one on me, but the CV driveshaft should make that a non-issue anyway.

How is the angle of the rear axle pinion and driveshaft? Are they within one degree of each other? Maybe it's time to remove the 1" mm kit since it does steepen the front driveshaft angle, though that shouldn't make the tranny grind. Are you certain the shift lever isn't being impeded by something making it hard to get all the way into gear? Finally, trannys shift slightly better with a good GL-4 synthetic lube. What kind of lube is in yours? Sorry I didn't have a specific fix, just kind of thinking out loud here TJ Edge.

[TJ Edge]

Interestingly enough, when I got the Jeep back after all the mods, it shifted easier than before, but the grind appeared as well. Easier meaning that the shift lever moved with much less resistance; and second gear was even easier to get into...unless you shift without thinking. Then it just grinds a bit and lets it drop into gear.

When the seal was replaced, I imagine they put in good ol' MOPAR stock stuff. I was going to go synthetic anyway; but this shifting problem appeared overnight. Also, it's there even after putting in fresh fluid. I would think that even basic stock fluid - when new - would make it shift like a dream (which it used to).

If I get rid of the MM lift, won't that make my driveline even worse? The engine would drop down, the belly-up is pushing the tranny and TC up, and the rear pinion is way below everything. The pinion angle is not quite perfect yet. I need to adjust the upper arms two turns out and the lowers two turns in. Then, it should be dead-on pointing straight at the TC output shaft.

Is it possible to screw-up a tranny by just taking out the Transfer Case and re-installing it?

[Jerry Bransford]

Oh yeah, ok, that makes sense now... that removing the mm kit would just make an already bad angle worse with the Bellyup installed. I'd probably make that adjustment to the control arms no matter what but it sure is a mystery how a CV driveshaft could do anything to make the tranny grind when going into gear. Good luck on that problem, let us know what finally fixes it!

[4ceTen]

My 5 spd never ground going into 2nd until after I lowered the transfer case an inch to compensate for a spacer lift I did last fall. I always suspected that I caused some binding somehow and messed up the synchro. You're the first (besides me) I've heard that has only had the grinding show up after a mod. Maybe there's something to it after all?