GDM

Active Member
Had this come up on our 55 plate TD6 today when my wife was going to collect her Father from hospital. She stopped the car and called the RAC. The patrolman read a fault code on the gearbox which apparently related to a valve but he did say that it sounded like it could be an electrical problem causing it. The RAC brought the car home and I moved it onto the drive fine, with the gearbox selecting drive and reverse with no issues. The gearbox was replaced with a reconditioned unit by the previous owner and it has only done about 3000 miles since then. When I drove it up the road the Trans. fail safe prog. illuminated again and the box is clearly locking itself into 4th. I have put my code reader on the car, it is not showing any faults with the transmission but it is only a fairly basic one.

Could it be the potentiometer on the transfer shift motor playing up? The motor itself seems to be fine as the box is shifting between high and low ratio with no problems. I have also read that it could be a bad connection on the gear selector wiring, is this likely?

Any help would be much appreciated, as I need to eliminate any potential external faults before I contact the company that supplied the gearbox.
 
It's not uncommon for replacement gearboxes to go quickly. A fault code relating to a valve sounds suspiciously like the ever present valve wear problem which is only ever solved by fitting a Sonnax (Sonnex?) valve block. I'd go straight back to the gearbox company and get them to sort it.
 
ive achived a hatric with my l322 gearboxes ,ps just check your battery is a1 first;)

Well I would rather not be doing the same, thanks!!

The battery died back in April, so that's fairly new. No signs of a low alternator output but I could test it just to make sure.

The 12 month gearbox warranty runs out on the 17th July, so I think I will call them and let them know there is potentially an issue with it.
 
Definitely get it back to the garage before the warranty expires and you could also try dropping Bemble a PM as he now has a business dealing with the ZF box but may be able to offer you some advice to go armed with or SaintV8 is his 2 I/C
 
Definitely get it back to the garage before the warranty expires and you could also try dropping Bemble a PM as he now has a business dealing with the ZF box but may be able to offer you some advice to go armed with or SaintV8 is his 2 I/C

It's all a bit complicated really. The previous owner had the box fitted by a garage in Essex but he sourced it from a company in Bradford. I am going to call the gearbox company tomorrow to register the problem, then get it to a local Land Rover specialist so that they can eliminate any other causes external to the 'box. If it is the box at fault , I can foresee things getting protracted.

Shame Bemble doesn't do the GM box as well but I will ask him if he has any advice.
 
It's all a bit complicated really. The previous owner had the box fitted by a garage in Essex but he sourced it from a company in Bradford. I am going to call the gearbox company tomorrow to register the problem, then get it to a local Land Rover specialist so that they can eliminate any other causes external to the 'box. If it is the box at fault , I can foresee things getting protracted.

Shame Bemble doesn't do the GM box as well but I will ask him if he has any advice.
But Bitnix has had a major result rebuilding his.....

I think he should go into business with Bemble/RRPhil ..... one does the ZF and the ther the GM... :D:D:D:D:D
 
Certainly low battery voltage and the transfer box shift motor potentiometer should be eliminated first as they are common causes of transmission failsafe but it sounds as though you’ve already done this. It’s possible that whatever code had been flagged related to a particular solenoid which would require further investigation/substitution but, as we’ve discussed many times on here, the vast majority of issues with the GM 5L40-E relate to the fact that the valve bodies wear over time through spool oscillation and the valves then leak and cross-talk. This reduces the hydraulic pressure on the friction elements (particularly the torque converter lock-up clutch) and they slip and wear, often right through the friction material to the metal backplate, generating metallic debris in the process.
A ‘reconditioned’ transmission is often stripped, cleaned out, and rebuilt with a re-manufactured torque converter and possibly new clutch plates where needed but the actual source of the issue i.e. the worn valve blocks/pump housing is not addressed so the problem begins again. The remanufacturer just hopes that it will last until outside of the warranty period. I would try to establish if anything was done to the valve blocks/pump housing during the previous rebuild, but it would also be useful to know what particular DTC had been flagged.
Any metallic debris in the fluid would also be a strong indicator that the issue is worn valve body related.

Phil
 
Phil,

Thank you for your reply.
I have just checked the alternator output and it appears to be fine, 14.15v only dropping to 14.13v with the lights on.
I called the company that supplied the reconditioned 'box this morning. To my surprise the guy was very helpful, he explained that the company had changed names and no longer did delivery of exchange gearboxes but they would honor the guarantee on mine.
I have booked the car into Keith Gott Landrover on the 20th, which was the earliest they could do. They are going to investigate and, if necessary, remove the 'box so that I can send it back. I will let you know what fault codes they get.
I have read about the valve body wear, so maybe that is something the reconditioners failed to rectify. If that is the issue, I guess it would be worth fitting a Sonnax valve block, as I intend to keep the car for a few years, and from what I have read these considerably increase the life expectancy of the 'box. Are these easy to source?

Glen.
 
I use these guys to test the (5HP24) valve body assemblies that I rebuild : www.valvebodiesuk.com so it may be worth asking them to quote? Forum members also seem to speak highly of STA at Aylesbury www.staautogearbox.co.uk for complete 5L40-E rebuilds (though I personally haven’t had any dealings with them). I’m sure other members will chip in with their recommendations. Although I have the Sonnax reaming fixture I only buy the kits for the ZF 5HP24 valve bodies I’m afraid.

Sonnax1_zpsxufwapw1.jpg


Sonnax3_zpsmo3xzxoj.jpg


Sonnax2_zpsxjk7qagq.jpg


Phil
 
Phil,

I e-mailed Valve Bodies UK and they came back to me at 9:50pm with a quote of £213-00 + VAT for an overhauled valve with Sonnax modifications. Sounds reasonable and excellent service to get a reply at that time.
 
Hey guys :D Failed gearbox and I'm here!

Phil as always murdering the post with crazy detail and best advice.

I think fair play to your wife for stopping the car and getting it transported home not causing any more necessary damage.

I think block rehaul for £255 is a steal at that price especially loaded up with Sonnax goodies.

I'm going to re-do my block soon.

@Saint.V8 I already rebuilt another gearbox which is going for sale soon. (it was out of a 530D tho)

I am no master but soon I will get the reaming fixture and will overhaul the block myself.

@Bemble Phil aren't you able to test the entire block yourself? What does the company you send them do that you can't?

There is not much to say here really if a warranty is covering you as that should cost you £0 for the box.
 
"Phil aren't you able to test the entire block yourself? What does the company you send them do that you can't?"

I can carry out a visual inspection of the spools and bores, measure the spools and their spring free lengths and vacuum test individual valves but, other than testing the winding resistance, I can’t properly check the operation of the proportional pressure control solenoids (current vs. pressure).
Solenoid testers cost around £5K and a dedicated valve body assembly test machine like a Hydra-Test is around £25k (www.hydratest.co.uk) and Valve Bodies UK have three of these machines.

There’s also a ‘Rolls-Royce’ solution from Fluidlogic

(which is a joint venture between John Mackie and BlueReach Automation) which is even more expensive, but a fabulous piece of kit. These are UK-manufactured machines and obviously the Americans also produce similar kit (SuperFlow/Axiline, etc.)

So far all of my rebuilt valve body assemblies have come back with a 100% pass score and clearly it’s my goal to get one of these machines myself in the future but I’ve a bit more saving up to do first! Donations welcome :):):)

Phil
 
"Phil aren't you able to test the entire block yourself? What does the company you send them do that you can't?"

I can carry out a visual inspection of the spools and bores, measure the spools and their spring free lengths and vacuum test individual valves but, other than testing the winding resistance, I can’t properly check the operation of the proportional pressure control solenoids (current vs. pressure).
Solenoid testers cost around £5K and a dedicated valve body assembly test machine like a Hydra-Test is around £25k (www.hydratest.co.uk) and Valve Bodies UK have three of these machines.

There’s also a ‘Rolls-Royce’ solution from Fluidlogic

(which is a joint venture between John Mackie and BlueReach Automation) which is even more expensive, but a fabulous piece of kit. These are UK-manufactured machines and obviously the Americans also produce similar kit (SuperFlow/Axiline, etc.)

So far all of my rebuilt valve body assemblies have come back with a 100% pass score and clearly it’s my goal to get one of these machines myself in the future but I’ve a bit more saving up to do first! Donations welcome :):):)

Phil

Sometimes you hurt my brain haha! And I was feeling proud of changing few clutch plates haha.
 
Keith Gott Landrover have now examined the Range Rover. They found the oil level and condition to be
satisfactory. The control module has logged the fault code 'Gear Monitor 4 Fault' and they have concluded that the vehicles has "an
internal transmission fault". This is consistent with the RAC patrolman's reading of a gearbox valve fault.

I have instructed them to remove the 'box and it will be going back to the company that supplied it.
 
Latest update.

The gearbox reconditioners stripped the gearbox and found that a seal had a nick out of it, which had caused the lack of pressure. They have sent the torque converter away to be checked, although it was replaced 3500 miles ago. The valve block was collected by Valve Bodies UK, who have re-built it, fitted a new lock-up solenoid, fitted the Sonnax valves and tested it. They offer a same day turn-around, so it is now on its way back to the gearbox company and will arrive there on Monday.
 
A quick update on this one.
Despite an arson attack on the gearbox company's premises (fortunately our 'box was in another workshop) and the owners house, they did get the gearbox reassembled and back to Keith Gott Landrover. They re-fitted it and we got the car back just over two weeks ago. All seems to be well so far, and the car has done getting on for 1000 miles in that time.
I just need to get the amount I have paid Keith Gott Landrover, and the carriage costs refunded, then it will be a reasonably satisfactory outcome.
 

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