L322 TD6 Transmission Issue?

Hi everyone,

I recently took in a 2003 TD6 Vogue in part exchange against one of my cars. It’s lovely and clean for its age and mileage with 136k on the clock. I know the previous owner and he’s had it for 6 years and has looked after it, but it’s not had much use recently.

Anyway, I liked the car, so started using it for myself. The car drove very nicely and the vast array of kit on the car all seemed to work fine with no issues. However, driving along one of my local country A-Roads, I was greeted with the message “Trans Failsafe Prog” of something along those lines. I couldn’t tell any difference in the drive though and the warning quickly went off again.

I carried on using the car and all seemed fine, apart from being greeted with the warning “HDC Inactive” upon start-up, even though I believe it works fine. Then, driving up a fairly steep hill the car seemed to struggle quite a bit. Back on the flat it was ok. Later on I drove up the local bypass, which is a mile long straight, bit of a climb and the car seemed to get to 50mph and then stop. If I floored it the revs rose dramatically, but the speed did not budge from 50mph. After that I heard quite a loud bang and clatter, but I wasn’t sure whether that was from me or something coming the other way! Again, once at the top and the flat, the car seemed to drive fine again.

After this I had the car plugged into diagnostics (sophisticated kit, not a basic scanner) and there was a surprising lack of fault codes. There were a few, which I’m sure were very old, but hadn’t been cleared, as they related to very specific faults which had been rectified as documented in the service history. One relating to fuel gauge for example. Under automatic transmission there were no codes and under transfer box there was only a pretty genetic looking fault relating to voltage. There was a pleasing lack of codes under suspension and all the many electronic systems.

Anyway, I cleared everything and then went out for another drive and made sure I carried a bit more speed before the ascent and managed to drive up there at 75mph with no issues. There was no acceleration beyond that and there was still possibly a little slippage, but couldn’t confirm 100%. I re-read the codes afterwards and nothing had appeared.

This was yesterday. Then this afternoon I pulled the car off my drive and turned round at the bottom of my close and then when I put the car into D there was no drive at all and the car just went to roll backwards. After a bit of playing and going into and out of low range, I managed to get drive and then carried on with my short journey with no issues. It did struggle with a steep hill more than I think it should, but did change gear halfway up and then seemed fine, so not sure...

Any ideas? I was possibly expecting to see a code relating to transfer box motor, but there was nothing. I know the HDC warning can be low voltage. I could try fully charging the battery, but diagnostics seemed to suggest voltage looked ok. Could a low-ish battery cause any transmission issues? I will be changing all fluids on the car as it’s due a service anyway and on a new-to-me car I tend to go all out when it comes to a first service.

Thanks in advance!

Mike

The GM auto box in those has a valve block made of cheese and the torque converter has a 2 stage lock up which fails and fills the box with destructive debris. The box often doesn't last much beyond 80K miles. If the oil has not been changed, there might not be much left in there either.

Datatek said:

The GM auto box in those has a valve block made of cheese and the torque converter has a 2 stage lock up which fails and fills the box with destructive debris. The box often doesn't last much beyond 80K miles. If the oil has not been changed, there might not be much left in there either.

Click to expand...

+1 and don't forget to change the oil cooler and pipes as they will be full of crap.

Just done the same box on an X5. Start the engine and listen around the bell housing for a scraping sound. Then drop the oil pan on the box. If there's shiny stuff In the pan and oil the box needs rebuilding. The pipes to the oil cooler can be cleared out but replace the oil cooler unit. Not expensive and certainly not as expensive as another box failure!! If there's metal the box is poisoned.
I do hope this isn't the case for yourself.

The transmission fluid expands when it heats up. This not only causes the oil level to rise, it also causes it to become thinner. Automatic transmissions have a lot of pressurised components that maintain their pressure through a variety of seals and valves. When these seals start to wear, transmission fluid can escape, lowering the pressure. In cases where a transmission is worn but not completely gone, it may drive fine when the oil is cold and viscous "how is it when cold"? When that oil heats up and thins out, it can start finding its way out of these worn seals and valves, causing a lack of pressure when applying a clutch.

Due to the idiots at GM's use of moulded pistons rather than regular seals re-sealing is not a simple job as it would be in other transmissions. ZF6hp26 "cough cough"

Also worth noting, also the "bang noise" 'tis worth looking into the output shaft on the 5l40 is well known to wear down to the point of no longer meshing . Worse still, the entire drive of the vehicle passes through this shaft, so when it wears down, the vehicle no longer drives at all and tends to make a horrendous racket when it tries.

The shaft is connected to a drum inside the transmission, and as the drum is at the back of the gearbox the issue is you have to gut the gearbox to replace it..

Oh and it can damage the imput for the transfer box too.


But ya'll knew that

I took it for a little drive this morning. Put it into reverse and reversed away without issue, put it into drive and jerked and slipped badly, struggling to drive forward, but it didn't stop trying and eventually when it did pull away it was fine, and continued to drive perfectly with no issues. Does that give any clues?

I have ordered a a service kit for the gearbox, transfer box, diff etc as well as a full service kit for the car as it is overdue anyway. Then can get the pan off and see what that shows.

@Bemble any words of wisdom? I can never remember if you refuse to touch the monster that is the early L322 TD6?

Again, this morning, started it up and it works in reverse no problems at all, they moving to D it doesn't creep forwards when you let off the brake and when you give it some throttle it revs and struggles to move forwards as if it's slipping, but keeping giving it some or press on and off the throttle and it will soon engage drive correctly. Once it has done that it will continue to work absolutely fine and pull away and creep exactly as it should.

Right, developments today...

I started the car this morning and had a play with my diagnostics machine to figure out where the gearbox oil temperature was so I could drop the sump on it and have a look inside, as I'd now got the correct Texamatic fluid and a new filter. What became apparent was that if I left the car to idle for a while to get up to temperature, there was no issue with slipping driving forwards.

Anyway, I drained the fluid, which looked pretty clean, but didn't look to me like it was the correct fluid and I think the level appeared a little low.

Then followed the unwelcome, but not unexpected sight of metallic particles on the magnet inside the sump. What quantity would make the problem terminal? Any volume of this? It didn't appear to be a high volume, but more than just a few odd "normal" fragments, There was a bit of paste like affair on the magnet.

Either way, I know this is the gearbox on its way out, but with fresh fluid and a clean out, how long is it going to last? I've found someone selling rebuilt units with the improved Sonnex Valve Block and new Torque converter for what seems a very reasonable price for what they are (not cheap of course, but I can fit it myself, so wouldn't be a cripplingly horrendous bill on an otherwise 100% functioning Range Rover in very tidy condition and after looking underneath I see it has had the updated front propshaft fitted. Aside from the gearbox it could ideally do with a new battery and the isn't too many miles left on the tyres, but that's about all it needs), I just ideally wouldn't like to do it straight away. Is there realistically any life left in it for, say 3 months as a minimum? I wouldn't be going too far in the car, so wouldn't be too worried about being left stranded and it's far from being my only vehicle to have to rely on it.

Fuel filter, change it, it could be clogged and starving for fuel

My car had 104k on the clock when I bought it and as it showed service due in -25k (yes 25k overdue) first thing was engine service, second was gearbox even though I didn't have any issues with it. I did have a nice little pile of filings on the magnet which indicated to me it was the original box. I think I got around 3k miles before it started jerking on long uphills, then I got trans fail safe twice which cleared after engine restart. That was enough warning for me to take it in for GB & TC recon. Just under £1500 and my own GB recon'd (not sure if they recon'd my TC or put in another one). Given the issues you're having IMO if it is the box you are deffo pushing your luck.

Fuel filter is being changed today. I concentrated on the box and diffs etc yesterday, but have had the filters since Monday waiting to go. When I had it idling for a long time whilst changing the gearbox oil it did start to smell a bit like stale Diesel. That powdery/sooty smell if that makes sense that you sometimes get with a clogged filter/cat etc. It did thrown the Trans Fail Safe warning once though at the weekend whilst driving. Although it only stayed on for a second.

I left it overnight after the gearbox oil change and from cold this morning it does seem to have improved somewhat on the initial pull away. It didn't creep on its own in D to start with, but only needed one reasonable rev to get it going.

I know the idea thing would be to put a box in now, but if it will run ok for a couple of months before really giving up the ghost, then bonus.

Always do the cheap simple things first and work from there, they usually need doing anyway, and it something you will have to do so your not going to lose any ££ on it and it gets the obvious things out of the way, battery oils fluids

You've nothing to loose running it until it fails. Just the inconvenience of when it goes...

I’ve just done a near 250-mile round trip in it. There were a couple of points where it seemed to go flat/get stuck, accelerating of an island on a dual carriageway, but eventually picked up. aside from that, no issues until the Trans Fail Safe Prog warning came on 39 miles from home and then went off after a few seconds.

There’s obviously some kind of issue, but apart from those couple of bits, it drove absolutely fine.

Well almost 2000 miles later it still drives exactly as it did. Fine the majority of the times, but sometimes uphill or during a long drive it won't change when it should. Since I carried out the oil change the problem with being slow to select drive first thing and slipping has disappeared.

IF the torque converter is at fault, can I just change that, flush the oil again and go with that as it's a lot cheaper? Or is it something other than the torque converter or will the filings from the torque converter (assuming that's where they're coming from?) be knackering up the rest of the gearbox?

Just a thought before spending £1000 on a new fully rebuilt box with torque converter.

The debris from the torque converter lock up clutch usually contaminates the box and the oil cooler which should be replaced if the box is done.

I think, if your inclined to have the gbox sorted and have mentally made the decision to do so... Go ahead and rid your self of any doubt and welcome the confidence of knowing all is good in the world of landrover...
For now.