ZF 3HP22 - goes then stops after 5 mins

[garyinwestoz]

Ive been trying to figure out what is the underlying issue with my 81 528i auto box

its a ZF 3HP22 unit
engine starts - and can forward or reverse okay

then if drive for like say 3 mins - - changing up and down gears AOK - then - all suddenly all drive to wheels stops. If I turn engine off - wait a few minutes- then start again can drive for 5 mins, before looses drive to wheels again.

I am wondering if anyone could have a look at this ZF 3HP22 manual

http://peugeot505.info/files/manuals/505_3hp22.pdf

and tell me what part I need to have a look at.

my suspicion is that its the hydraulic block - or maybe the pump - but would a pump stop working after a few minutes?


I complied a drawing sheet from the manual to assist.



Ive attempted to remove the hydraulic block, but 3 of the torx head screws I managed to strip!
so I removed the rear plate instead and checked out the pistons -(no 14 - 20 ) I'm not sure but I think the No 13 main pressure valve might be stuck (not sliding freely) - unless there is something that is meant to stop it of from coming out - the two springs holding it in are real stiff!

[garyinwestoz]

If I could I would have left the Hydraulic block assembly fixed to the transmission and just remove the 2 cover plates to get at the pistons, but I couldn't get a front plate off due to interferenec with filler hose - so I removed the whole assembly .

So now that the assembly is out, began to dismantle it.

The block has 2 halves with 2 end plates and an extra part bolted on it.

ancillary part removed







It looked like I needed to remove the pistons before separating the 2 halves.
I unscrewed the cover plates and removed the springs, pistons and caps. taking photos of each part as it was removed
Then I unscrewed the last 2 screws which kept the 2 halves together.


The separating plate and gasket were quite stuck to one half, I'm not too keen on separating the plate and gasket - so left them as is and gave all the rest a good clean.

block separated into 2 halves


]

There was a bit of muck in a few channels and on the outer casing, which brake cleaner, rag and air spray eventually got out. I did all the separating and cleaning in a large laundry bucket

Here is some photos of the parts.

separated the 2 halves of the hydraulic block



the 2 ends of the block has 2 clover plates , which cap the end of all the pistons.





there were 3 very small "caps"( about 5mm diameter with a slight cupping and centre hole ) which fell out, thankfully I heard them hit the tub- hopefully I got the right position for them.

[garyinwestoz]

some of the pistons/valves have holding clips, which I recorded how they were orientated






The repair manual has these indicated - here is my note sheet a made on it.

[garyinwestoz]

Once all clean up - the repair manual says to reassemble in reverse order.

I basically started at the bottom ( of the drawing ) and worked my way up to the top - leaving the main pressure valve+ converter pressure valve (no 13 + 14) - as I was not too sure how that was to go, as it consisted of 2 valves, 2 springs and a sleeve. When I dismantled it - it came out differently to the drawing.

photo of disassembly
first out came the springs


then the main pressure valve with sleeve



Now back to reassembly.

Any way, I got all the other valves, spring and pistons in , plus their required 3 clips and 3 reducing cups. I checked the movement of all these and they seemed free enough.


The springs need a bit of pressure to clamp the cover shut - I ended up using a clamp to hold it whilst I screwed in the screws.


I then bolted the other half of the assembly -leaving the main pressure valve to the very end.


I installed the main pressure valve according to the drawing - although the drawings does not seem to show a valve that fits inside the sleeve (no 14) I hope it works out okay.

Here are the parts laid out ( main valve not shown as its inside the body already.

sleeve, converter valve, outer spring, inner spring ( + main pressure valve - not visible, as I'v already inserted into the body)


put together


looking at main valve inside body




Then I installed cover plate. Due to the double springs - the cover plate takes alot of force to get the springs to compress so the screws can then be screwed in.





Once I was happy with that, I installed the external parts.



Its now ready to be reinstalled to the transmission

I need to get some more bolts though as some of them didn't survive very well the chisel head method of extraction! M6 x 80mm I think they are.



Reassembly took me maybe 70 mins - as did is slowly and double checked an redid a few valves as I got the clips in the wrong slot - (which prevented the valve from moving.)

[garyinwestoz]

I just found this valve body overhaul page for the ZF 4HP22EH which maybe helpful to understand these things

http://twrite.org/shogunnew/files/jason ... ebody.html

Having now looked at this, I wonder if I have the cups orientated correctly and if the checkballs need to be checked? Its hard to tell in the Peugot service manual I have.

[garyinwestoz]

Ive reinstalled the valve body into the car and taken it for a couple of drives - seems to engage 1 an 2nd sorta okay - but only at high revs, doesn't want to go onto 3rd yet - I am wondering if the fluid is bit low.

But it does take off and rev ( to 5500) in 1st wonderfully now!

Couldn't drive for long as the engine steamed up!

reverse is -- erre --- ordinary to almost non existent - ie real slow to engage - but goes once going - sort of .

[garyinwestoz]

Anybody got any idea or drawing of the accumulator cup orientation for the 3HP22

I think I may have reassembeld them in the wrong orientation (all are down).

I found these 2 images of a 4HP22 hydraulic block, but the layout is quite different, I dont know what the passages relate to, to transfer that design intent to the the 3HP22.

[canada karl]

Dosn't look like a lot of Fivers have had that auto trans apart to help you out? Ever thought of switching to a 4 or 5 spd manual trans? Are there still E12's at the wreckers in OZ?

[Mike W.]

The ZF3HP22 is the most common A/T in E12s, but not many people work on them themselves.

This is the best I can do, image wise. I do have a 62 page manual on 3HP22's for Peugeots that I could email to you if you want, I obviously can't post all 62 pages. I doubt there would be much difference in assembly, but I don't really know.

[garyinwestoz]

thanks Mike,
I do already have the Peugot 3HP22 workshop manual.

That scanned image is the one I cant work out exactly what the orientation of the pressure caps is ( No9)

whats your take on them ( no 9)
this is my guess.
on left side
1 (in line with No 16) - down
2 (just above No 17))- down



on right side
3 (just above No 22) - up






hmm, I might have put them in the wrong way
chow

Gary

[garyinwestoz]

I just found a photo I took whilst dismantling - Duurrr which seems to indicate the cups and their orientation.

I also have a photo which indicates the position of the checkballs in the upper half.



here is rotated and compared to the diagram



They all appear to be facing up.

I looked at my photos of the reinstallation - and I seem to have installed them all facing upwards ! fancy that.

[Mike W.]

I looked at my photos of the reinstallation - and I seem to have installed them all facing upwards ! fancy that.

As an amateur who has been inside an A/T just a couple of times, you can't take too many pictures of the process or make too many notes.

[maybeillbuyit]

Gary. Good work here. Great to see someone working on one of these. Hope it all works out for you

[tlake]

Like Mike W. said, you cannot take enough pictures when dismantling automatics. This is usually work for automatic transmission experts.

If all else fails try Clifford's Automatic Transmissions, a place in your neck of the woods. I remember someone on First Fives mentioning them years ago concerning a rebuild of the ZF 3HP 22 automatic, I remember because their initials made the word CAT, and their logo was a cat Apparently they did a great job, at a very reasonable price, with a warranty, and they had a very good name. Contact details below:

Clifford's Automatic Transmissions CAT

Yeah, automatics are a different story to manual transmissions, really skilled work. Worse than a/c.

[garyinwestoz]

well

the last drive I took, I added more fluid and well- it changed into the 3rd gear and was nice an smoothish - boy 20-80 in about 7 secs - seemed effortless.

however,,

when I got back to the workshop and went to go in reverse - urr nothing.

I turned engine off

let is sit for a 30 sec s or so restarted and reverse engaged and I managed to part it back under cover.

hmmm - need to relook at the book again!