Alright so I'm getting rover ready for nov trip to superlift orv and I h e some driveline noise I want to be rid of. When I shift p to r or d to r or r to d I get a large clunk that feels like gears comIng together or shaft engaging. Also when I let of the gas pedal and letting engine breaking take over I get the clunk. This is a 98 no shifting issues usually smooth except when let of the gas and shift as stress above. There is no rubber coupler on my unit. I have had this before an I helped it a little by tightening a screw behind the rear drive shaft input from transfer case after I fixed rear diff with new pumpkin and gears from junk yard( super clean parts) new u joints in front shaft post lift rears are ok for now and soon to be done. I can't imagine the cv I'm about to change could be the culprit but it could be as well. But are there any educated ideas I have not yet check transfer fluid and hvent had my swmbo home to shift it while I'm under it to examine. But I need a good lead to trace down. Sound sounds more from front end and mid engine/ transfer case area this doesn't sound so much like reg shifting to gear noise but more
Intense. Things I've done to front end include wheel bearings springs shocks +2", I need to put on new track rod, and replace driver front cv axle since it clicks and clunks itself here and there. So any guesses as to why I get shifting noise/ clunk ? Remember it happens with release of gas pedal at any speed as well.

 

These transfer cases are big huge gears, they will make a clunking noise. The best way to quiet them down is to replace the fluid with the heavier fluid (85w140).

Go ahead and drain the transfer case. There is an inspection plate that you can easily remove and do a visual inspection and then reseal it.

Of course whenever you are going to drain the fluid on your diff's and t/c make sure the fill plug will loosen prior to removing the drain plug!

You can also use the 85w140 on the front and rear diff's as well as the t/c.

It is best to resolve all your known issues at home before you go to an off-road event like that to improve the chances of you having a good time and being able to drive it back home afterwards.

 

Dude mines been clunking like that for the last 65,000 miles.
You will be chasing a red herring, they clunk, it is gear lash, only fix is new stuff.
Like Danny said heavier gear lube makes it not as harsh.

 

Ok yea Danny I have been meaning to change gear lube since last check. And yes I'm working my list now so we are ready to roll in nov at superlift. In the spring I did a large R&R list and work before we went and this time I'm doing it again " be prepared" BSA. Even after checks still blew rear diff last time all four spiders and pin shredded leaving only ring and pinion left, but rover still got us 4 hrs back to memphis. And yes I always check fill plugs before draining that can really put u in a bind if you don't. And I've known they clunk but it seems so severe I know diffs and tv are solid gears which is great but gear lash seems violent sometimes, I'll re lube diffs and tc I used 85/140 when R&R rear diff sO I'll do it in tc too add some Lucas and hopefully it will quiet it down a bit. But all that clunk with release of throttle is still "normal" for gear lash in discos? this part about during throttle release is petty new lately. I appreciate that clangs back guys give me more confidence in my everyday rover fixins. Since I've had the rover 1 yr and 2 months Ive done all my own work with confidence gained from these boards at LRO and here. I've read lots of what u guys hVe said on both boards and others and it helps alot. I'm no idiot when it comes to motors and cars but I'm no expert either but with the rave and these boards I could strip and rebuild that truck with confidence. Hell ripped apart top end only 3 weeks into ownership and did heads. And she started up the second time I turned the key after all that. Only reason not the first time was cause I forgot to plug in main connector at coil pack lol checked my list and low and behold only thing not checked was "connect coil pack fitting" lol thanks for the confidence everyone here on boards. I hope to continue to contribute when and where I can.
Steven& Ashley

 

Check your rear driveshaft ujoints. Some play/clunk is to be expected. Excessive play/clunk is probably ujoints. Hard to say if yours is normal or excessive without being there to hear it.

 

I just rebuilt my front prop shaft and the clunk is the same. I ignore it now.

 

... Never mind...

 

By all means check ALL the U-joints... If none of them are bad then it's just gear lash..Crawl underneath the rig and watch the driveshafts as someone you TRUST shifts in and out of FW and REV with engine at idle. If it's a U-joint you'll be able to see and hear it..Between the transmission and the wheels are a LOT of gears leaving a lot of space to take up when changing directions or when loading/unloading the driveline..

John

 

I noticed a big difference when I changed the gear oil in the transfer case & both differentials. (75w-140, I think.) The whole truck got much quieter & smoother.

 

Gearbox/mainshaft input spline wear. Source an early DII's unless you want to rebuild. LR issued a TSB, TEC370296R.