Hi there I was wondering if anyone out there in the UK was aware of any auto gearbox rebuilder who actually modifies the valve block of these GM boxes by fitting SONNAX liners. Having read so much great info on this site (especially from RRPhil) regarding this problem with the soft aluminium valve bores,surely by now one of the re manufactures should be offering this service. I have found the auto box fitted to this early Mk 3 RR to be a very good unit when operating as it should but as my truck has now covered 103000 miles I would like to think that if I spent good money having the gearbox overhauled it might cover another hundred thousand. Cannot see this happening if the bore problem is not addressed.

Agree 100%. I think you may be better going directly to a valve body specialist. There’s a couple of places here that you could ask :

1. Valve Bodies UK Ltd. on Merseyside (www.valvebodyuk.co.uk)

2. Beds Automatic Transmissions in Luton (www.valvebodytech.co.uk)

I should emphasise that I have no personal experience of either of these companies (so I’m not recommending them) and just found them on t'internet. However, they’ve both invested in Hydra-Test testing machines which are £25,000 a time.

Phil

Just out of interest, is it box off to get to the valve bodies on these? I only ask as I saw another post talkng about one of the V8 boxes, where it is mentioned that the valve body can be removed in situ.

On all of the L322 transmissions the valve block assembly can be removed from underneath without the need for the transmission to come out.

Phil

Thanks Phil I am in process of contacting companies you mentioned. Have also emailed Sonnax in the States. Will post as soon as I hear from them. There must be hundreds of folks out there who have unknowingly purchased rebuilt GM boxes that have not had this wear problem addressed!

RRPhil wrote:

On all of the L322 transmissions the valve block assembly can be removed from underneath without the need for the transmission to come out.

Phil

Don't forget the tc is also a very weak point on the GM5L40E gearbox.
Then the gearbox definitely has to come out.
Imo the last of the td6 is at least 9 to 10 years old now, so if you are thinking of keeping it may well be worth the investment.
Myself I really want a tdv8 and move on from the bmw days.
greg.

I guess My thinking was that there are a number of TD6 for sale that have had the gearbox and TC replaced. RRPhil mentioned on another thread that the TC will wear at an increased rate if the old valve bodies (either original box or recon) hadn't been replaced with the sonnax units, so if you were to whip out the valve body and finish off the job that the recon company perhaps should have done, before any major TC damage had occurred, then that might be a good move.

Mackie in glasgow fit sonnex valves on gearbox rebuilds also replace torque converter

Cheers Swiftman contacted Mackies of Glasgow and they quoted a price of £1500+carriage and vat. This means I will have to get old box removed and re built unit fitted at my local Independant LR garage.Am now looking into that. Great Website with loads of top class help available. For interest have owned 2002 TD6 Vogue for 6 years now, bought with 80000 on clock,now done 103000. Problems have been early front prop and diff failure (recall). New rad.+ air condenser , rear wiper mechanism repair.( last 3 repairs done at home) Air bag warning light - new body control ECU. Xmas lights on dash caused by broken wire from left rear wheel sensor. Service every year at home and use Castrol Edge in motor

I had mine done in Luton 3 years ago. They change Torque Convertor and fit sonnax if after testing it is needed. Mine did and had full overhaul for £2300. I have clocked up another 63000 miles with a lot of towing and still going strong. The Best 4x4 by far, so long as you have deep pockets.