Transmission Failure

[wickedwazza]

Hi, have a transmission failure and worried where to start.

Was driving down a steep gravel hill into the campsite with caravan (1.5t) on, probably only down 10-15kpm, and the transmission clunked and started to grid and had a shake in the front-end. managed to get to the site. And each time tried to get into forward or reverse would jump a couple of inches and wouldn't select a gear.
Was then about to drive up the hill without trailer still grinding and skipping and once up to speed was fine, and able to drive at 100kpm with no noise... But when stopped in 1st or 2nd gear had the same issue until it got up to speed.
Seems better while cold and once warmed up had the clunking at low speeds, probably 2nd gear.

Following day it wouldn't go into forward or reverse (in high range). Managed to get into Low range, and was able to select all gears and reverse, it does jump an inch or so when selecting gears but was able to drive the caravan back up the hill and drive 50km to a big town in low range at low speed, where got a tow truck to bring us back to Melb.

Where do I start, could it be the solenoids in the transmission, or internal gearbox related . Am thinking its not internal as Low range works.
Checked with scan and no faults at all!!

Vehicle: L320 2010 RR Sport, 3ltr with 137,000KM

Of course it would happen on the 1st day of christmas break with a long trip planned.
Thinking of getting it to Peninsula Rangie in Franskton, but they seem closed still.
Ideas?
thanks
Warren

[loanrangie]

First step is get codes read and see if there are any faults logged, 2nd would be to check the fluid level on the trans. Trans shouldn't clunk so you may have other coincidental things going on , i would also look at a transfer case calibration.
If you are anywhere near i can scan it for you but it sounds like you might be SE or bayside area ?

[wickedwazza]

Thankyou for the offer, am down Bayside. Already checked and no codes are reported which is very strange.

Current thinking is the chain to transfer box.

[haydent]

Ive rebuilt the D2 ZF 4HP22 after a ZF reco'd box failed twice after stuff all kms, once with a dead TC, and the second time from a burnt clutch pack i suspect from stiff valve and loose bolt in valve block i found.

Your L320 likely has (mine does too) the ZF 6HP26

Auto's are my biggest gripe with cars, as feel its the least diy/mechanic friendly, hardest to access/diagnose, and get parts/tools

Try to get it diagnosed, maybe there's something that can be done/tried, otherwise consider finding a wrecker or wreck on marketplace and get the transmission and tc from it and swap it. a wrecker you will get some warranty but it will likely cost more, potentially more than the car is worth spending on

Hired labour will likely add 1-2k

It might also just be the end of this car. Like i said, i tried the proper route, replace my original dead box with a zf re-built one and even that failed. And in hindsight wasnt financially worth doing.

Once the old one is out you can try pulling it apart in your own time and keep it as a spare...

[Graeme]

The splines on the gearbox output shaft and the transfer case input shaft may be very badly worn in which case shortly the splines will be totally stripped. The splines are greased at assembly and are a known failure point. I had my MY12 L322's TC removed at 150K to regrease the splines. The grease was dry but the splines undamaged.