help! jatco td4 auto box

[Nodge68]

I'm going to rebuild my clutch pack and check the piston at the same time, when the weather improves, if I ever get the garden and garage sorted.

I'll do a bit of a write up once I've done the job.

 

[Hippo]

Looks like mine's starting to do this too. Slips in 3rd 4th and 5th not too bad when cold. If I lift of the gas the revs drop back down and the auto box grips again and carries on....I'm pretty sure the symptoms are pointing to this cracked reverse piston I've been reading about. Now my next question is what parts do I need to buy, and can I fit them all without any special tools, as I've read you need to compress some kind of spring in the reverse piston drum? Is this true?... are the guys that have done this job still on here? Any pointers on what extra I may want to change etc.... any photos, info you guys can provide will be most welcome.

Sorry to hear yer having trouble with yer auto gearbox. There's a number of parts lists available online for the Jatco JF506E which is the auto you have fitted. You can buy individual parts as well as service kits. The video below shows someone stripping one down.

 

[Jayridium]

Looks like mine's starting to do this too. Slips in 3rd 4th and 5th not too bad when cold. If I lift of the gas the revs drop back down and the auto box grips again and carries on....I'm pretty sure the symptoms are pointing to this cracked reverse piston I've been reading about. Now my next question is what parts do I need to buy, and can I fit them all without any special tools, as I've read you need to compress some kind of spring in the reverse piston drum? Is this true?... are the guys that have done this job still on here? Any pointers on what extra I may want to change etc.... any photos, info you guys can provide will be most welcome.

The reverse piston can be accessed from the top of the box, with your knees at the bumper, looking aft, its at the back right hand corner of the top of the gearbox visible as a circular cap held in with a snap ring (circlip without the eyelets. From memory the spring isn't all that strong, there are writeups somewhere on twinterweb, most likely on here about removing the piston to reseat the reverse band after the infamous mistake of mistaking the reverse band retaining bolt as a filler plug.

 

[Jayridium]

If you do a bit more forum archaeology, back end of last year / /beginning of this year Nodge had a thread about his autobox, in whcih I posted a link to the jatco rebuild manual that you might also find useful.

 

[jedi]

If you do a bit more forum archaeology, back end of last year / /beginning of this year Nodge had a thread about his autobox, in whcih I posted a link to the jatco rebuild manual that you might also find useful.

Thanks this would be very useful..I'll search again see if I can find it.

 

[jedi]

The reverse piston can be accessed from the top of the box, with your knees at the bumper, looking aft, its at the back right hand corner of the top of the gearbox visible as a circular cap held in with a snap ring (circlip without the eyelets. From memory the spring isn't all that strong, there are writeups somewhere on twinterweb, most likely on here about removing the piston to reseat the reverse band after the infamous mistake of mistaking the reverse band retaining bolt as a filler plug.

I thought this was the part/parts needed as the OP of this thread mentions. Don't think this is accessible from the top..I think I know which piston you mean thou..the small accumulator ones???? I don't think these cause my problem? Or do they? My symptoms point to this cracked piston I the drum assembly as far as I can tell?? But I could be wrong..
http://www.transpartsdirect.com/sho...verse-high-clutch-2-pistons-99-up-fp03-19-48/

 

[jedi]

Sorry to hear yer having trouble with yer auto gearbox. There's a number of parts lists available online for the Jatco JF506E which is the auto you have fitted. You can buy individual parts as well as service kits. The video below shows someone stripping one down.

Sorry to hear yer having trouble with yer auto gearbox. There's a number of parts lists available online for the Jatco JF506E which is the auto you have fitted. You can buy individual parts as well as service kits. The video below shows someone stripping one down.

Thanks hippo...I belive it's accessed from the non engine side of the auto box through the wheel arch as I think the OP mentioned, By removing the end plate and I belive you have to drop the engine a bit to gain access.. But never done this so I don't know...

 

[Nodge68]

beginning of this year Nodge had a thread about his autobox, in whcih I posted a link to the jatco rebuild manual that you might also find useful

And I've still to conclusively find the actual issue, which is why I've now got a complete clutch pack to go in to the thing.

 

[Jayridium]

I thought this was the part/parts needed as the OP of this thread mentions. Don't think this is accessible from the top..I think I know which piston you mean thou..the small accumulator ones???? I don't think these cause my problem? Or do they? My symptoms point to this cracked piston I the drum assembly as far as I can tell?? But I could be wrong..
http://www.transpartsdirect.com/sho...verse-high-clutch-2-pistons-99-up-fp03-19-48/

And I've still to conclusively find the actual issue, which is why I've now got a complete clutch pack to go into the thing.

I previously posted the ATSG (Automatic Transmission Service Group) manual for the Jatco JF506E in the thread nodge had started, which is why I mentioned it, dig up that thread. If you find that thread you'll get the ATSG Manual - which has the full teardown and rebuild documented and illustrated, and that would show how to get into the particular piston you are on about.

What I'm thinking of when saying it is the piston on the top right back corner of the gearbox is that in the PDF I've attached to this post, it's that piston that gets dismantled to make it possible to reseat the reverse band without having to remove and dismantle the gearbox, so I am/was thinking it must be that piston that is the reverse piston?

I'm not an expert on automatic transmissions by any manner or means, and certainly not specialist enough on this particular gearbox to analyse its failure modes and assist you in the diagnosis, so I'll leave the diagnosis to you or others who know more than me. However, in the case of the reverse piston, I have reason to believe it is indeed the top one we spoke about earlier.

 

[Jayridium]

For familiarisation, the red bolt is the infamous one that many mechanics have mistaken as a filler plug:

 

[Jayridium]

 

[biketeacherdave]

Most problems with this box are cured with new shift solinoids which usually burn out and can be change from the front of the engine bay, new oil and job done. Kits on the bay

 

[Jayridium]

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

 

[jedi]

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

Thank you kind sir...I will have a read.

 

[jedi]

Most problems with this box are cured with new shift solinoids which usually burn out and can be change from the front of the engine bay, new oil and job done. Kits on the bay

I've already changed the 3 duty solinoids a while back for a harsh shifting fault. Oil should be ok, looks/smells ok, its had 4 to 5 flushes a while back..... I pretty confident it's not solinoids, I've been in there for the hard shifting fault..all seems ok...

 

[jedi]

This was the thread I was looking for...the guy mentions a special tool of some sort on page 2 post 5 of this thread. Will this be needed? Also he mentions he got a new "already built up" reverse piston housing kit? as a special is required also to fit it all together??? Can anyone shed more light onto these tools?

https://www.landyzone.co.uk/land-rover/jatco-drive-in-1-and-4-only.192505/

 

[Hippo]

Thanks hippo...I belive it's accessed from the non engine side of the auto box through the wheel arch as I think the OP mentioned, By removing the end plate and I belive you have to drop the engine a bit to gain access.. But never done this so I don't know...

Access is quite tight on the v6 to get the side plate oft the auto, as the side plate is quite deep. There's not much more access on the Td4. Ideally you need to take the engine/gearbox/ird out of the car. But that's not straight forward. You can disconnect things and turn the engine/gearbox/ird clockwise as you look at the car from the front, so the side plate can come oft the auto, underneath the chassis rail it lives next to. That's not straight forward either but it's a way others have done it. You have to turn it quite a bit to get the side panel to come oft, under the chassis rail it lives next to. Easier if you have lifting gear to control weight and height. If you look at the video below it shows just how deep the side plate is.

jatco side plate

 

[jedi]

Thanks hippo...yeah that side plate it's quite a chunk of metal...I will see what I can do and keep this thread posted.

 

[Nodge68]

Thanks hippo...yeah that side plate it's quite a chunk of metal...I will see what I can do and keep this thread posted.

I'm going to remove the side plate (looks like a Face Hugger (from Alien) plate on my Jatco once I've got my FL2 on the road.

It's possible to remove it without taking the gearbox off, but the box mount does need removing, and then the box can be lowered enough to remove the plate, with all the internal components in one lump.