I have a 95 Disco I with the auto tranny and 3.9L V8. The issue is as follows:

When it's first started up and I drive away the tranny won't upshift out of first until I hit 4500-5g's rpms (bad idea) or I sit and let the vehicle warm up for a few mins and have the tranny in neutral to circulate the tranny fluid. After it shifts to second, it will act as normal. It seems like it needs to build up pressure in the system or something. I checked in the RAVE and it says that it's probably a sticking primary regulator or a clogged filter. Well I was hoping it was just a filter so I did a fluid change and ran it, then I did the filter and what a PITA that was.... What an engineering marvel! Anyways it still does it although it shifts nicer now.

Can I get to the Primary Regulator to clean it and unstick it? Is it in the CONTROL UNIT ASSEMBLY? I have found a used "good" tranny for $500 and I am thinking of attempting to swap it in for mine but I was wondering if I can simply unbolt the control unit assembly and bolt it into my tranny in the truck after dropping the pan? Anyone know if this is possible?

Also how much of a job is a tranny swap in one of these? Do I have to drop the tranny with the transfer case or can I just drop the tranny with the motor and transfer case supported from underneath?

Please any ideas on what the problem is and the solutions would be great. I have a 2-3 day window to get this thing done. I love the disco and want to drive it like it should be driven.

Thanks

 

I dont know if you can just change the control thingy or not.
have you tried any of the mystical wonder transmission additives out there yet?

 

I haven't tried any miracles in a bottle yet but I am tempted. Any suggestions?

 

There's probably not a miracle here.

You said you drained out the burned varnish and filled with new, replaced the filter.

I'd bet (no money) that the fresh fluid will unstick your primary regulator soon - if it were me, I'd shift (foot on brake) a half dozen times D - R and let it sit for an hr.

Do that several times and then go for a drive, she may come back to life - The only trans failure I've heard of in 7yrs was a young gentleman posting how he'd pull semi's out in the winter (wanted advice)

luck,greg

 

I will try that.. I should have also mentioned that there were metal shavings in the pan and clutch material as well..... One piece of the metal almost looked like a chaved piece off a metal o-ring or something.

 

Well, that sucks, tiny powder may/or may not be a disaster, but shavings are never good.

At this point, your option is to drive it or pull it apart.

Even if it starts working OK, I'd keep an eye open for a known working one, r&R the filter, clean the pan and be ready for swap.

luck,greg

 

Thanks for the info Greg. Do you know if you can just swap out the control unit from a good spare and just drop the pan and just put it in my existing tranny? Is the primary regulator in there and is it serviceable from the bottom?

Thanks

ps how huge of a job is it to drop and replace the tranny in this veh?

 

I wouldn't swap anything from this trans to "new" one, or vice-versa, unless I was 110% certain it was pristine - the grit you've witnessed has distributed throughout inside, it would take a complete teardown to remove it.

I've done several rebuilds in the past, (not land rovers) it's not for the average mech as there's generally special tools involved, immaculate large work area.

If you opt to buy used, pull the pan b/4 you pay.

As I indicated, some crap in the pan will be expected, but not alot of metal (usually old oil sludge)

The ZF by itself probably weighs 100lbs.(will feel like 500 if you're on your back),
same with the xfer case, it's dangerous w/o a lift and trans jack, but I've done them on the ground with my floorjack & a helper

If it were me, and I wasn't certain or didn't have every possible tool, I'd price around local shops to just R&R the trans for me. I'd supply all parts.

luck,greg

 

ok thanks, I've done trannys on vehicles without the special jacks as well. I am just wondering if anyone has done a write-up with pics? I have downloaded the rave as well.

 

Typically we only do write ups on common stuff, the transmissions on these trucks are pretty hard to kill.
I would keep driving it and see if it gets better, maybe change the fluid again in a few thousand miles.