727 engages really harsh - fix?

[loborph]

My 727 engages reverse with an attitude. It shifts thru the forward gears without a problem as a I travel down the road but I get stout 'ka-plunk' when I put it reverse from park and sometines as I put it in drive from park. Is there a cure for this? thanks

[gsmikie]

check your u-joints

[John V]

What he said

[kreb]

ditto

benjamin

[710 Burner]

From what I have been told, this is a pretty common 727 problem.

[Bluesky4x4]

Mine does the same thing. I have a lockup torque converter in it and figured that had something to do with it (PO installed the convertor). Are you guys saying it can come from a bad ujoint, basically putting it in reverse it slams the slop out of the ujoint?

[mandoneer]

also if there is alot of slop in your axle or x-fer that could be happining (when mine was doing it it was the rear axle --re shimmed it and set the ride depth and no more prob )

[andy d]

kicking the engine off of high idle before taking off helps too.

[Kevin718]

I have had this problem as well as a vehicle vibration problem when sitting at a stop light.

While I probably have some slack in the U-joints and/or transfer case, lowering the idle speed has made a significant improvement.

I discovered the vibration problem was less at idle, but was still there. Turns out the transmission mount is very loose and allows the entire transmission/engine/exhaust to move around causing the vibration. I am thinking that correcting that problem may also help with the clunk when shifting into reverse.

[Kimbrough]

One of the best fixes I've done for my Jeep is install a new transmission mount. - Autozone @ $20. No more clunking and shifts smooooth!!!

[gsmikie]

Originally posted by Bluesky4x4:
Mine does the same thing. I have a lockup torque converter in it and figured that had something to do with it (PO installed the convertor). Are you guys saying it can come from a bad ujoint, basically putting it in reverse it slams the slop out of the ujoint?is the converter electric ???? if so where does the wire go into the trans ?????

[FDawgg]

loborph - Did you figure out/fix your tranny issue? Mine is '87 w/ 727, sat for 2-3years.

I have the same 'clunking' when accelerating from stop and only when cold - after warms up for 5-15minutes depending on temp outside, it is fine from there. Other than that shifts and is strong. Rear axle, ujoints, rest of drive train is fine. Fluid looks/smells fine.

I am thinking torque converter and pressure doesn't build up for some reason w/ cold fluid. Gsmikie asked about converter was electric - I don't know, but not thinking has to do b/c is consistent and not intermittent like a short, so not looking at anything electrical at moment (if in fact is electrical).

Personally it doesn't make sense how a torque converter would go out or only do this when cold, but why I am making my virgin post.

Though haven't anything on the 727 (like ig mod on ignition), is there a modulator, etc (easy to replace/cheap) that typically goes bad on the 727's? I don't mind changing in off chance it will help and may have to replace 'soon' anyway.

[Breeze]

I read an old post where the conclusion was that the klunk from park to reverse is common and cold not be stopped in most cases by changing all parts. That's interesting about the benifit of a new trans mount. My vibration damper/bushing thing is loose. I should get a new mount and damper bushing thing.