GU Patrol - Clunk when stopping???

[Dirty troll]

Hi Shaun,
Just browsing and I saw your post mate. I thought I'd offer my similar story.

I had a problem awhile back with my GU. A knock only distiguishable just as the vehicle motion stops. I could hear it as Ive had the vehicle awhile, but it could easily be missed if not paying attention.
At any rate I replaced bushes pushed and pulled flexed and swore and basically chased my ass for awhile until after considerable time spent underneath I noticed a slight witness mark on the gearbox mounts and then noticed how sagged they really were. It seems the gearbox mounts were worn to point of making a slight knock as it came to rest.

I replaced these myself and problem solved. Good luck, I hope this helps.

Frosty

[BigRAWesty]

Very interesting outcome on this one.. Hopefully the little but if oil helps..

Mine used to do that, it was the bottle jack in the rear. I put some rags around it to stop that.

To stop this issue I simply wind up my jack against the lid so it's positively held in place.. No more rattles..



Kallen Westbrook
Owner of
Westy's Accessories

[Scottyc]

Hi Shaun,

No progress for me. I took mine back to the dealer who's mechanic couldn't find any issues and was actually using this thread for troubleshooting (there was a printed copy left in the car when I picked it up). I had my own mechanic take a look. He laid underneath the car while I shifted from drive to reverse and back and thinks the slack leading to the clunk is definitely in the gearbox or transfer case. Suspicion of the transfer case is furthered by the fact that the Patrol is EXTREMELY hard to get into low range. Looking at the parts view of the transfer case, I'm suspecting it's a problem with the shift sleeve on the high/low part of the system. The shaft from the gearbox through the transfer case is in two parts. The sleeve joins the two parts for normal driving and high range and a shift fork slides the sleeve forward splitting the shaft in two and directing the drive through a secondary shaft from the input then back to the output. A split or worn sleeve would (in theory) lead to the clunking AND difficult High/Low shifting. For now, I'm just dealing with the clunking and will pull the transfer case and have a look when I get time.

I've bought another transfer case for parts but having a bit of trouble getting it picked up as it's in a rural area. Once it arrives, I'll hopefully be able to have a crack and I'll let you know what I find.

Cheers,

Scott

[Scottyc]

So almost 2 years later, seems I finally got this sorted. I bought a replacement transfer case but hadn't got around to swapping it in. I had, in the mean time, read elsewhere that it might be the propeller shaft causing the trouble - more specifically the slip yoke. I'd discounted this as a drive shaft place had already taken a look while it was on the car and said everything looked fine other than that I'd used too much grease on the yoke.

Whilst browsing ebay, I came across a used rear shaft for a 4.8 auto for under $100 so I threw a bid on and won. I fitted it this weekend and lo-and behold, the clunk is gone. Feels like a different vehicle. The new shaft has a few dents so is probably going to cause some vibration at speed but I'll try and get the old one reconditioned when I have some spare cash - sorted.