Topic: Reverse knocking

[Gr8Ride]

Folks, need your help as I may have made a dumb*@@ mistake yesterday.  Was tooling around all morning and she was running fine.  Stopped on a very slight incline and went stomping out in the woods with my kids.  Upon return to the jeep, battery was dead - no notice.  Think I made the mistake of trying to push start (slope start) in reverse.  No dice x 3 tries.  Managed to get her turned around and slope started fine in 2nd.  Replaced battery.  Took for a drive.  Upon engaging reverse and letting out clutch, a noticeable knock emits from underneath, commensurate with vehicle speed while in gear.  If I mash the clutch, noise disappears indicating it's in the tranny to me.  After about 10 miles of driving around, no probs in any other gear but prob didn't go away for reverse.  Definitely a metal knocking.  Same jeep as in my profile.  Any ideas/solutions?

[Mozman68]

Hmmmm...never heard of anyone trying that in reverse.  I guess I never will now.

I have no clue as I am a dumb ass...but I've always been taught to start in 2nd gear...going forward.

Sorry...I'm sure someone on hear with more mechanical skills than me will chime in with the right answer.  Hopefully you're not completely screwed.

[lanulos89]

i kno a guy who popped his axle shafted, pop starting in reverse.

[Jeffy]

Well, I've never heard of anyone trying to bump start in reverse.  Reverse is geared lower then 1st and the speed needed to get the engine to kick over is faster then you should use reverse or 1st with.  The engine will try to stop the vehicle from rolling and something can/did give.

I'm guessing the noise only happens in reverse since you didn't mention it happening on the way home.  You could put the transfer case in neutral and then try putting the transmission in reverse and see if it still makes noise.  If it is then I'd drain the oil and see what comes out... :shock:

[Gr8Ride]

Thanks folks.  At least now you know of one dumb@$$ wishing he knew then what he knows now.  Was simply a matter of situation and convenience - damn.  Yes, noise only happens in reverse.  I did put the transfer case in neutral and put the transmission in reverse and it still makes a nice steady thumping noise while idling. Can't drain yet as have to drive it to work this week.  Hopefully, it's isolated to only reverse and it will not self destruct or harm any fwd gears.

[Guardian7]

Sounds like you may have damaged a tooth on the reverse gear, since I just rebuilt my AX5 I can tell you that reverse is very different from the other gears and not designed for any torque. I actually have a spare reverse gear if you need one because I bought a used trans for the 3rd & cluster gear to fix my own. The white pointer shows the straight cut reverse gear on a seperate shaft which has no bearings or synchros. An easy gear to change!

[Gr8Ride]

Thanks!  I'm sure that's all it is, just don't want any metal lodging in another gear and screwing that up as well.  So, here's the start of a week of hoping nothing else happens.  Send me an e-mail as I'm sure I'll need the gear and let me know how much you want, shipping, etc.  Also, could use your recent experiences with yours to avoid pitfalls while doing mine -from removal of tranny on.  Thanks again!

[Jeffy]

Sounds like you may have damaged a tooth on the reverse gear, since I just rebuilt my AX5 I can tell you that reverse is very different from the other gears and not designed for any torque. I actually have a spare reverse gear if you need one because I bought a used trans for the 3rd & cluster gear to fix my own. The white pointer shows the straight cut reverse gear on a seperate shaft which has no bearings or synchros. An easy gear to change!

Actually, reverse is stronger then the other gears because it's 'different'.  Reverse gears are straight gears which are inherently stronger then helical gears.  This is why they are used mainly on race cars.  Straight gears don't have syncros and don't really need a clutch to shift.  Tis is why there is an interlock for reverse.  Still even though they are stronger, they still don't like heavy shock loads like dropping the clutch while rolling.

[Guardian7]

Glad to help is I can, were are you located? The design seemed weak because the reverse has no bearings on the gear or shaft like the other gears and is not synchronized either so you should be carefull.