Freelander 1 Td4 Jatco 3rd to 4th Flaring, Slip- Solved

Just a thought, as it is a 2000 my, wonder if there has been a software update for the auto??

Wondering whether to swap my 2002 MY auto ecu into it to test the theory?
Don't see why it wouldn't work?

andyfreelandy said:

Wondering whether to swap my 2002 MY auto ecu into it to test the theory?
Don't see why it wouldn't work?

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Try it, the TCM is a straight swap, so it would prove or disprove the theory.

Are they all plug and play? There appears to be at least 4 different codes.
UHC000030
UHC000120
UHC500110
UHC500160

Will see what the types I have are, but any harm in trying any one of the above?
New territory this!!

My other theory, must stop thinking about this !!

Is.....that the gear changes 3rd to 4th and then for some reason the TC unlocks and lets the revs rise?
I can eliminate this by disconnecting the TC lock wire. PScan doesn't monitor the TC lock and unlock command unfortunately.

Possible??

I believe there are 2 main types of TCM, the pre 2003 which has 2 speed sensors, and the post 2003 which only has 2 speed sensors.
I believe the harnesses are the same, just there's no internal connection inside the TCM for the missing sensor on the later type.

I've got a late TCM here, which I tried in mine when it was messing around, but it didn't help, so I took it out again.

I don't think fitted a non compatible TCM will do any damage, most modules these days are protected against wiring errors and things.

andyfreelandy said:

Is.....that the gear changes 3rd to 4th and then for some reason the TC unlocks and lets the revs rise?

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The TC clutch should unlock on the gear change, as the TC needs to slip to provide a smooth change. The TC clutch should only lock up after the TCM decides all parameters are satisfactory, before locking the TC clutch again.

Progress update. One change of fluid. Couple of hundred miles. Fault changed immediately after fluid change as described above. It changed 3rd to 4th then a few seconds later revved and reselected 4th.
After about 30 or 40 miles it improved significantly. It remains in that improved state in that it only revs about 2 or 3 times per hours drive rather than pretty much every change. Every fault occurs when 2 things are present. 1. A fully warmed engine and hence transmission. 2. An incline.

There is no 'slip' caused by the incline, purely it decides to go into 4th, then into sommat else and rev then back into 4th.

The good news is that 4th is not failing, when it is in 4th it will take any hill at any speed.

Slightly flumuxed but encouraged!!

Have bought another ATF to do another change. A replacement auto ecm (it was very cheap!) and will eliminate old or duff software. Will also do another code read, but the key question is: what influences the gearbox when going uphill to make a different change to the flat or downhill? ?
5 pints of real ale to the correct solution!!!

andyfreelandy said:

what influences the gearbox when going uphill to make a different change to the flat or downhill? ?
5 pints of real ale to the correct solution!!!

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ATF takes time to clean, so I'd expect it to continue to improve as it's cleaned more.

Road speed, engine speed and engine torque output.

Been reading up on this and it appears early Jatco 2001 boxes had a weak reverse clutch piston. Jaguar did a recall. The MG Rover site has a DIY repair through the wheel end of the gearbox.
https://www.the75andztclub.co.uk/forum/showpost.php?p=586577&postcount=33

I will do another fluid change but fear I am buying time if the above has occurred. What I want to prevent is filling the box up with clutch dust!!
Anyone know a good auto speciist that would do this with the box in the vehicle?
Looks like special tools are required.

Also Jag recall notice.
A technical service bulletin #1021 which included Land Rover provided a solution with an upgraded reverse piston and high clutch housing.
I shall be calling LR to find out if I can get this done!!

Reading previous threads on this issue, @Nodge68 was this the issue that you bought spares for?? If you still have them John, might be able to do a deal.

andyfreelandy said:

Reading previous threads on this issue, @Nodge68 was this the issue that you bought spares for?? If you still have them John, might be able to do a deal.

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I got a complete spare clutch pack for mine, and mine was slipping in 4th all the time. I believe this was due to me overloaded the clutch pack by using excessive torque (the Synergy was at maximum), and towing too much weight up a hill at full power as it changed up. This also screwed up the TC clutch, so these gearboxes are actually quite fragile, especially where the maximum torque loading is being reached or exceeded.
I never got to fix my Jatco as the FL2 came along, and I needed to shift my FL1 fast.
Unfortunately I let the FL1 go with a big box of spare gearbox parts in the boot.

That's a shame!!
But the above is interesting and many Rover and Jag sites back up the manufacturing fault.
LR stance is currently that they are unable to 'verify' the technical bulletins that I sent them!!

I have contacted Jatco in Japan to ask if they had an issue with the component in 2001 and whether LR UK were advised to take action.
I guess I'll be doing it. Looks fairly straightforward to drop box on one end, remove end plate, then it looks more complex when you start pulling out circlips and clutches!! Is it doable DIY??
Don't want to take box out if not essential and having stopped using the car don't want to pay for full recon box.
What is opinion, any pitfalls??

So here is the plan!!

Continue debacle with LR HQ regarding the fact that they omitted recall over duff manufactured reverse piston in MY 2001.

Have requested info from Jatco Japan regarding whether there was a corrective action issued to LR HQ.

Put vehicle on lift and lower gearbox to access side plate.
Remove side plate and take out speed sensor and then the whole reverse / high clutch drum. First item out of this end apparently.

Take entire drum to local gearbox specialists who will replace pistons, seals, friction material etc and reassemble.

Replace drum and flush with a couple of fluid changes.

What could possibly go wrong!!??

andyfreelandy said:

Take entire drum to local gearbox specialists who will replace pistons, seals, friction material etc and reassemble.

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I think most gearbox rebuilders would like to see the whole box, and replace anything suspect inside, I know I would.

You've already practiced removing the gearbox once, so doing it again would be easy.

I accept that is true. However, it it the difference between a hundred quid and about a thousand!

Based on the mileage of the box and the fact that I know it has been used very gently since the fault appeared, I am prepared to take a small risk on the rest.

I have, just ordered an 80k jatco in order to have a play before hand and also to get the later style reverse piston and high clutch assy as they are seemingly hard to get. I will get the spare rev/high drum refurbished and then fit it.

Always feel happier when I can pull one apart on the bench first and see what is going on.
I may then get the spare box refurbed for my 2002 Td4 as it has nearly 200k on the box now.

andyfreelandy said:

Magic forum this!! As soon as I posted the above I found the table. Jf506E rebuild and repair manual.
Off to test......

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Jayridium said:

This is the full ATSG jatco JF506E manual
https://www.mediafire.com/file/kj4e9kgkpx2mg72/JF506E.pdf/file

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You're welcome. Hope it helped?

Thanks yes.
I had it saved on my pc but couldn't find where I had seen the table.
Thanks for the original posting of the info.
I have found exploded views, spare part references and other bits that I will be sharing too.

@Jayridium looks like the link has expired ?

Here are some other useful Jatco reference documents found while researching my next job.

I just re-activated my ancient account to post here as the 2002 Td4 auto I bought cheap in February has the same 3-4 shift issue. It's definitey not low mileage at almost 128K miles and it also only does it when warm.

Fortunately it's a third car and most drives are sub-30 mins so it isn't a major issue. I've found that it gets worse with lots of 3-4 shifts, presumably heating up the oil. if I cruise for a bit it gets better. As described, it changes into 4th but then seems to unlock until revved. I'm going to get the oil changed as I understand that to be a non-DIY friendly job but will then see how it goes, the 2-3 shift seems to be at a surprisingly high RPM too so it will be good to see if that is sorted.

This old hippo doesn't have a rear prop or VCU, which is why it was cheap but means it isn't worth chucking too much money at it and I'd be interested in what budget repairs are possible. I'll be keeping an eye on this.

Matt2000 said:

As described, it changes into 4th but then seems to unlock until revved. I'm going to get the oil changed as I understand that to be a non-DIY friendly job but will then see how it goes, the 2-3 shift seems to be at a surprisingly high RPM too so it will be good to see if that is sorted.

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Mine starter doing that, it would initially disconnect drive for a bit, allowing the engine to rev freely, before it would slam into 4th with a bang (sometimes producing F4 on the dash). Eventually it lost 4th altogether, and nothing seemed to fix it, a fluid change didn't, or replacement of all the solenoid valves.
Stranger was when F4 was on the dash, suddenly there was drive in 4th, which in my mind discounted the clutch pack.