New guy,old comanche,late intro.

[mj2stay]

first of all,thanks to ComancheRob,Pete M,Eagle,and ekulrenlig for the info on trannies.I have been way busier than I really care to be lately.I think I have been all over more than any place else for the past two months.Any-way,I bought the best truck that I ever had in '86.I put 301,000 miles on it. I let my two teenage sons drive it to school for three years each.(and it survived),with one more son to go starting next year.When my Comanche was new I got pulled over by the D.P.S. for speeding and got away with a warning because all he wanted to know was how I liked my new Comanche. I knew it then that this truck was special.So now I've got a vibration somewhere, I think it might be 4th gear in my AX4,thank you very much! I guess that will be my next repair.Well ,I'm looking forward to touching base with some others who know whats-what with a great truck that was phased-out way too soon! [/b]

[Mitch]

since you said 4th gear I will give it a stab... by starting simple, hopefully not insulting you in the process :)

 

4th gear could mean highway speeds, what condition are your tires in, are they balanced? could the belts be going in them?

[87manche]

then pull the front driveshaft and take a loook at the cardan joint at the top. After 261K miles in my MJ it wanted rebuilding, and caused a deep driveline vibration at highway speeds.

Try driving around without the front DS for a few days to see. Assuming of course it's 4wd.

 

I suspected that my AX-15 was going bad wen I bought the truck, 20K miles later and the damned thing just won't die.

[Duner]

check all of the u-joints and if its 4wd check that the shift slider bushings are still on the shift fork there may be nothing left of them and this can cause a deep vibration at 40+ mph. I was amazed that mine gave up so quickly on a low fluid issue in the transfer case.

[mj2stay]

I guess I could have mentioned that it's a 2wd, 4 banger,strictly for street use.Well,I had the wheels balanced about 800 miles ago,the u joints changed about 3000 miles ago (they were definitely bad). Here's what it's doing,0 to 50,no vibration. between 50 to 55 mph there's a small vibration,4th gear of course, when you get past 55 the vibration is very noticable. once it gets to about 65 to 70 the vibration goes away. and when I'm slowing down,and push the clutch in, the vibration eases up a bit but is still there from 55 to 45 then it goes away as I get slower.What would that mean when I push the clutch in,cause then it doesn't really have any load pressure on it does it, right? I've done a visual on my tires and they seem to look o.k. still a lot of tread,no uneven wear,no out of round.What about the drive shaft,could that get out of balance? It would be nice if it could be an easy fix, but if it wasn't for bad luck, I'd have no luck atall !!!!

[Rokhound]

my truck did the same thing as your saying. I just rotated the tire front to back and it went away.

[mj2stay]

One tire or both? I'll try that today. Thanks!

[87manche]

betwwen 55-60 is when most tire vibes become apparent, I'd rotate them front to back as suggested.

[mj2stay]

Yep I'll do that here pretty soon. I'll post the results.

[Rokhound]

all 4 if also if you have an extra set throw them up front and see what happens.

[JeepcoMJ]

check your front ball joints...if they're bad they can throw everything out of balance.

[Mitch]

My trackbar was causing that same issue, lots of trackbars cause that issue, have someone aggressively turn steering wheel back and forth (turn the ignition key only enough to unlock the steering) and see if you can see "play" on either end of the trackbar.

 

Good luck, I hate steering problems!

[JeepcoMJ]

that may be my problem...vibrates on the front left side. i thought it was my left upper control arm.

 

for me, it's not the ball joints, u joints or LCA bushings...those are all new less than 20k ago. but i didn't replace the track bar...or the UCA bushings.