Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

Re: Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

Well the situation isn’t quite so bad with the 6HP26 transmission because the same transmission & transfer box combination are also used in the Range Rover Sport and LR3 & LR4 (Discovery 3 & 4) so replacement transmissions are much more plentiful (& therefore cheaper).

Having said that, it would be a great shame to replace your transmission without trying a simple EDS6 solenoid swap first.



Of course the fault could lie with the torque converter itself (the ECU is reporting the fact that, even though it is being signalled to do so, the torque converter lock-up clutch is failing to engage) but surely you have to give a replacement solenoid a shot first! So how handy are you with a set of spanners?

Phil

Re: Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

Sam,

You may want to begin by downloading the workshop manual for 2006-onward models, if you don't already have it :
http://www.fullfatrr.com/forum/topic17623.html

There’s also some information here : http://www.rangerovers.net/forum/6-range-rover-mark-iii-l322/44034-zf-6hp26-teardown.html

I can also provide you with more detailed instructions if needed.


As I see it, you have three options :

1. Swap two of your three ‘yellow cap’ solenoids around (EDS6 being one of them of course ) and see if the problem moves with it. Adv – least cost, no waiting. Disadv – two solenoids to move, plus they’ll have to recalibrate themselves

2. If you’d be willing to fund the shipping costs I could send you a second-hand solenoid to try. If it makes no difference, just return it. If it fixes the problem, you keep it and PayPal me $25 or whatever. Adv – low cost & risk. Disadv – you’ll have to wait for the thing to arrive from the UK and I’m about to go on holiday for a week

3. Buy a new solenoid (the ZF part number is 0501 213 960) from someone like The CTSC http://www.thectsc.com/index.php?p=product&id=165&parent=52 or Cobra Transmission http://cobratransmission.com/index.php?main_page=product_info&products_id=3012030 Adv – brand new part sourced from the US. Disadv – Risky; an expensive way to find that the problem is not caused by the solenoid ($100+)!

It’s probably worth mentioning that one of the advantages to ZF of having the transmission ECU as part of the Mechatronic unit, along with the valve block, is that all the solenoids can be calibrated to the actual unit at the factory. By replacing the solenoids you’re upsetting the original settings and the transmission will therefore have to modify its adaptions for the new solenoid. You should really, therefore, get the transmission adaptions cleared at the start of the process, which would require a trip to the dealers (though you could also get the latest ECU software update at the same time)

Phil

Re: Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

Dale,

Unfortunately I’m not familiar with BMW fault codes, though your ‘060 Selector Lever Position’ fault could, I guess, relate to the inhibitor switch. Your switch will be the same as the Range Rover one, except for the length of its wiring harness (as your connector will be mounted under the transmission, closer to the switch, rather than on top of the bellhousing). There’s some information on checking its function here :

http://www.rangerovers.net/forum/6-...-transmission-errors-issues-5.html#post253892

(The ticks in the table show where continuity should be measured between the +ve pin and the remaining pins in each selector position)

In fact, it’s probably worth checking the condition of the pins in the connector too as it’s so exposed to the elements, just in case you have a dodgy connection?

It’s always worth repeating that the number one rule when it comes to the TRANS FAILSAFE PROG message is to check that the battery & its charging circuit are up to scratch before turning attention to the transmission.

The reason I asked about the 2-1 downshift is that we’ve seen a few reports about it before on the 5HP24 (not to be confused with the 6-speed gearbox where it’s the most commonly reported problem with the 6HP26, by far). With the 5HP24 the consensus seems to be that it’s related to high fluid temperature. My concern is that I’ll get your transmission apart and not find anything significantly amiss. As the seal & gasket kit, plus the three steel feed pipes, filter & B/C-clutch bearing cost around £230 (i.e. the minimum cost of a complete rebuild) that’s clearly an expensive way to find out that your transmission is fine – plus the hassle of getting it out and back in to the vehicle.

As a first step, would it be worth me checking & rebuilding just your valve block? This can be removed without removing the transmission from the vehicle and would ‘only’ take me around 4 days to complete. Cost would be around £50 i.e. £40 for return postage (unless you want to drop off & collect?) + £10 for a new plate gasket & to cover the cost of cleaning materials.

Phil

Re: Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

Bladerunner2 said:

Hi Phil

What worries me about the Autobox problem is everything was fine up until the ATF Radiator blew and the car went into Failsafe Mode and then the garage under filled the box with the wrong spec Fluid, then after a couple of hundred miles they had to take it to East Lancs Transmissions in Bolton for them to drain and refill with the proper ATF and fit a new filter because the box just didn't feel right at all, the 060 code began to pop up after all of this, although the box was back to normal as far has smooth changing was concerned, this wrong fluid and lack of fluid business do you think this could have caused any permanent damage to the inner workings of the box, one chap in Preston someone suggested I ring said that since Dextron III was put into the box all the clutches would be contaminated and need to be changed, then another so called specialist said Dextron III would do no harm to the box? I work as a Taxi driver in Bolton so my vehicle is my living and although right now I can still work in it, the thumping problem is ever present and I just fear that at some point its going to go altogether?

Dale

Click to expand...

Dale,

Clearly Dexron III is an ATF so there’s unlikely to be any short-term chemical compatibility issues with the transmission’s various components (bearings, seals, bushes, friction plates, etc.) - especially after only 200 miles - it’s more an issue relating to the friction modifier packs used in the fluid. This is obviously fundamental to the performance of the six clutch packs, but particularly so to the torque converter lock-up clutch where the fluid’s static-to-dynamic friction characteristics are especially critical due to the control of low slip speeds in its ‘continuous slip’ mode (<100rpm).

The signals provided by the engine, turbine & output speed sensors allow the transmission ECU to self-adapt throughout it’s lifetime to maintain shift times (through the modification of clutch control pressures) so the transmission does have the potential to make some allowances for changes in fluid friction characteristics, but the tolerance on this allowance will have boundaries.

I have stripped a number of 5HP24s where I drained off red fluid (i.e. Dexron) rather than LT71141 (which is honey coloured when new)

and these transmissions were in a sorry state. Unfortunately, as I don’t know the history of these transmissions (and how long the fluid had been in there), it’s difficult to be sure that the fluid was responsible for the transmission’s demise but my instinct tells me that it played its part. Certainly Dexron III was never designed as a ‘lifetime’ fluid.


I’d wondered how you managed to clock up 16k miles in only 7 months – your job would explain that! Because it’s inconvenient/costly for you to have your car off the road for any length of time I’m now thinking that it might be better if I just build you another valve block assembly to quickly swap over

continued ……

Re: Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

I have lots of spares but they tend to be Range Rover ones i.e. for the ‘032’ variant of the 5HP24

There are 27 different versions of this transmission and I would need to establish exactly which model yours was to see if I have the right parts available. I think, being an E39, yours is a ‘022’ model but I really would need you to check. The model number is stamped into a green identification plate on the LH side of the transmission at the back. It’s the number that begins ‘1058’, below the transmission’s serial number. For example the picture below shows a ‘029’ model (1058 000 029) which is from a BMW E53 (X5).

Phil

Re: Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

I got the solenoid. Thank you Phil.

Could you post instructions/tips on how to remove the solenoid (after the sump is removed). Looks straight forward, but wanted to make sure `8)

Here are pictures of the solenoids on my rig. I figure I need to replace the last one at the bottom....on the other side of the electric connection tab.

Cheers,
Sam

Re: Can I replace my ’02-’05 V8 gearbox with one from a Jag/BMW?

Hi Sam,

Glad to hear that the solenoid got there okay.

Yes the EDS6 solenoid is the one at the bottom of your first picture


Unlike with the 5-speed ‘boxes, where each solenoid has its own individual electrical connector which can be removed with the valve block in place, the Mechatronic unit for the 6HP26 has to be removed from the transmission so that the complete electrical/electronic control module can be removed.

My previous ‘teardown’ post describes the valve block removal.

Once you have the Mechatronic unit on your bench you need to undo just the six bolts that hold the black plastic electrical/electronic control module to the valve block



and then remove it (there are a couple of dowel pins too)



You’ll then see that there’s a retaining plate, which clamps all the solenoids into the valve block, that needs to be removed (9 screws) and you’ll then be able to get your EDS6 solenoid out and perform the swap.