Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: robpark on December 27, 2006, 08:52:31 PM

Title: New YJ - Gearchange & noises (!)
Post by: robpark on December 27, 2006, 08:52:31 PM
Hi Guys,

Just got the new YJ home ('93 4.0 Limited, manual), having spent most of the afternoon on the M6 southbound from Manchester to Birmingham (was everyone on the road today??) - anyway.... all sound to begin with, but by the time I got home (3 hours later) changing down to second gear was getting awful noisey, even with a lot of care it usually made some grinding noises (gear box oil low maybe?). Also I noticed that having come off the motorway, almost everytime I pulled away there was a sort of rubbing/rumbling noise that went away very quickly but sounded like it could have been a shot CV re-centering itself, but there was no noise or vibration once moving above walking pace. (On a short test drive pre-Christmas & throughout most of the journey all was fine). Sorry this is all a bit vague, but I thought I'd just throw this out there & hope someone could just give me some possible routes to follow to get a better idea of what's going on.

Many Thanks,

Rob.
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Post by: Bubba on December 27, 2006, 08:56:36 PM
check all the fluids first
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Post by: MK1 on December 27, 2006, 08:57:39 PM
Possibly a worn 2nd/3rd synchro hub.
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Post by: Mike Pavelin on December 27, 2006, 09:25:11 PM
The noise on takeoff is almost certainly the limited slip diff in the rear. Try changing the oil. Use 75W90 GL5 gear oil and a bottle of Mopar friction modifier (from a Jeep dealer). If the noise doesn't go away, or returns quickly, the rear diff may need rebuilding or replacement.
With the gearbox, is the clutch clearing alright? if so, again try an oil change (75W90 GL5 again) and see what happens. could be 2nd gear synchro if all other gears are ok.
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Post by: robpark on December 28, 2006, 02:20:16 PM
More news - some bad  :( , some not quite so bad  :?  ...

Clearly new oils would be a good idea, but the gearchange seems just to be weak syncro on 3rd to 2nd - as long as I pause for a moment in neutral it's fine (I don't suppose that would be a quick & easy fix?). The bad news is re. 'noises'. I thought I ought to try 4wd (why didn't I do this when I test drove it - doh!) - and 4H was a bit clunky, 4L was horrendous - real nasty clicking and grinding from front axle (I think from driver's side), the wheel would barely turn. I could only bear to move a few feet & got it back into 2H asap and within a very short time it was fine again. Seems it will turn ok, but won't be driven. Is this likely to be the UJ by the front hub?

Can anyone recommend a superb, but inexpensive, Jeep garage near Bromsgrove??  :cry:

Cheers,

Rob
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Post by: Tank on December 28, 2006, 04:19:18 PM
Im by no means an expert and stand to be corrected,but you may find that the 4h and l may improve after a little use and change the fluids in the axle.These are hardly used and really should be driven in at least once a month but hardly anyone does.
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Post by: Mike Pavelin on December 28, 2006, 05:25:55 PM
Did you drive it far in 4WD? You have no centre differential action in 4WD, so any sort of turning will cause severe axle and transmission windup resulting in all kinds of nasty noises and steering difficulties. Does it drive ok in 4WD if you engage it and only drive in a straight line?
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Post by: Bubba on December 29, 2006, 12:17:07 AM
i will have a looksy if you want to have a ride up to j2 of the m5
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Post by: robpark on December 31, 2006, 09:27:52 PM
Well, looks like the likely culprit has been found - front UJ's are pretty well shot (offside rather more than nearside). So hopefully a phone call to Lighthouse for the bits and some spannering and all will be quiet again. I imagine it will also benefit from an oil change to gearbox & diffs.

Many thanks to V8 Bubba for all the help today, and everyone else for their comments and suggestions.

Cheers,

Rob.