4HP22 Auto 'box problem 1989 Highline

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: GRNSHRK, ron, bfons

Post Reply
Pod
Platinum Member
Platinum Member
Posts: 4492
Joined: Tue Mar 16, 2010 8:32 pm
Location: usually in the barn, Kent, England.

4HP22 Auto 'box problem 1989 Highline

Post by Pod »

Hi guys, looking for any ideas before I drop the gearbox and dump it!

I bought the car with an unidentified autobox problem which the owner decided not to attempt to fix. The problems appear to be forward gear selection (clutch pack?) and the car's propensity to BANG! into gear when either forward or reverse selected at tickover.

I think the solution's either a rebuild or to replace with a working unit. However, maybe someone has had a similar problem in the past and can point me towards an easy fix [-o<
User avatar
Brucey
6 Series Guru
6 Series Guru
Posts: 10077
Joined: Fri Apr 09, 2004 7:17 am
Location: Cambridge, UK

Post by Brucey »

the jerky selection indicates a hydraulic problem and the lack of forward drive strongly indicates an 'A' pack failure. The former can cause the latter.

New fluid and clean filters might fix the former issue but only a gearbox strip/repair will sort the latter.

If you are sourcing a replacement gearbox do note that there are several slightly different versions; not all EH boxes are the same. for example.

Do note that because many of the parts interchange in the gearbox, a used box may yield useful spare parts, even if it too has a failed A pack; IIRC the plates are similar to those used in one of the other clutches.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Pod
Platinum Member
Platinum Member
Posts: 4492
Joined: Tue Mar 16, 2010 8:32 pm
Location: usually in the barn, Kent, England.

Post by Pod »

Thanks, Brucey.
Chris Wright

Post by Chris Wright »

Here is some more info on the transmission with a link to rebuilding it (with photos):

viewtopic.php?t=8437
Pod
Platinum Member
Platinum Member
Posts: 4492
Joined: Tue Mar 16, 2010 8:32 pm
Location: usually in the barn, Kent, England.

Post by Pod »

Thanks, Chris.........I think an auto box rebuild beckons - at least I'll strip it down and have a poke around :wink:
User avatar
Brucey
6 Series Guru
6 Series Guru
Posts: 10077
Joined: Fri Apr 09, 2004 7:17 am
Location: Cambridge, UK

Post by Brucey »

if you are going to open it up and try and fix it, I'd suggest using new oil and filter, running it up to temperature and running through all the gears a few times. This should get everything a bit cleaner before you start having to deal with sticky valves etc. New ATF has a high detergent value and should keep everything nice and clean; by contrast most boxes that end up behaving like yours are filled with something that looks more like treacle...

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Pod
Platinum Member
Platinum Member
Posts: 4492
Joined: Tue Mar 16, 2010 8:32 pm
Location: usually in the barn, Kent, England.

Post by Pod »

Thanks, Brucey. However, Ron's made me an offer I cannot refuse........ :wink:
Post Reply