[RRPhil]

I recently bought a ZF 5HP24 transmission for a Range Rover, off eBay, for £50. It was listed as being from a 2002 model with 95,000 miles on the clock and the description just said “needs reconditioning”.

It cost me another £53 to get it shipped the 230 miles from the seller to my house.

I took a few photos as I stripped it down in case anyone’s interested:

After draining the fluid I removed the sump pan – magnets had the ‘normal’ amount of debris attached. So far so good

Filter is next – date stamped 2002, so it’s obviously never been changed

Next off is the valve block assembly

Everything looking okay, so far

Park lock mechanism and selector detent and shaft are removed next

Followed by the B, E & F clutch feed pipes and the C & D clutch jump tubes

Moving to the back of the transmission, the rear cover & park lock gear are next

The next job is to slacken off the F clutch drum retaining screws. This drum is the very last part to come out of the transmission but it’s important to slacken the screws off now while the transmission has some weight in it because they’re countersunk and are always stubborn to get out.

Then around to the front end of the transmission to unbolt the bellhousing

Followed by the intermediate casing (which houses the oil pump)

‘Tower 2’ pulls out next – which is basically the A & B clutch assemblies with their respective shafts

The first clue as to what was wrong with the transmission now emerges! The axial needle bearing which separates the B clutch hub from the C clutch drum has worn to the extent that many of the rollers have come out of the bearing cage.

Loose needle rollers trapped in the B clutch hub – all worn to a taper

Having seen exactly the same thing on previous Range Rover transmissions that I’ve rebuilt I know where to look for the cause and sure enough, having separated the A & B clutches, I can see that the O-ring which seals between the B clutch drum & the input shaft has failed

The resulting leakage here prevents the A clutch generating sufficient clamp pressure causing it to slip under load and, as it’s used in gears 1-4, the control system detects the slip and protects the transmission by upshifting all the way up into 5th gear – usually with a bang – each time the vehicle sets off from rest

A & B clutch assembly unassembled

The C clutch & front sun gear drive sleeve then pull out

Followed by the D/E clutch assembly…

…the epicyclic geartrains…

…and then finally the F clutch & 1st gear sprag assembly


So, apart from the failed O-ring & the consequent damage to the axial needle bearing, everything else looks in great condition.

A new bearing costs £7 and I’ll replace the A clutch friction plates which is a further £30. The failed O-ring is part of the overhaul kit (£145) so with new fluid & a new oil filter, plus the £50 I paid for the transmission and the delivery charge we’re looking at a grand total of just less than £400 for a fully reconditioned transmission – not bad.

Phil

 

[Dave S]

Most excellent. Wish you lived in NY, NY. You are an amazing wealth of information and I am sure others will agree you deserve much thanks for sharing.

 

[gooddfella]

Wow thats awesome man. Great information as always.

 

[gw2doc]

good stuff Phill, thank you very much for that, with the amount of trans probs that show up on here and your awesome right ups, any chance you are going to put together some step by step rebuild videos together?

 

[remington]

Wow great post. I don't have 1/100th the skill or knowledge to do what you did but it's interesting to read about it. I'll stick to eye surgery.

 

[adara]

Bold, brave and beautiful!

 

[umitbat]

Great post.
How about clutch pads?

 

[Gazellio]

Stunned by how these things were invented in the first place!

Your a very clever man RRPhil :clap: :clap: :clap: :clap: :clap:

 

[SGW]

Excellent, precise and professional write up as usual from you Phil. Your knowledge is unriveled in this field.
Stewart.

 

[drdread]

Wow great post. I don't have 1/100th the skill or knowledge to do what you did but it's interesting to read about it. I'll stick to eye surgery.

:lol:
I was thinking the same thing, although I'd be sticking to the simpler task of Trauma Surgery. :wink:

 

[robertofollia]

Thank you so much for such wealth of knowledge, and for sharing that amount of info. It's priceless.

Thanks again
Robert

 

[CJD]

Phil, in addition to your mechanical ability, I am truly amazed at your organizational skills to lay the process out in pics and narrative for us all...truly impressive!!

Now if you have time for a quick question...do you think there is anything that can be done to these to save the o-ring from failing as a preventative measure, or is it just a "wait till it fails" part?

Thanks again...John

 

[torqueni]

This is real helpful thread long story short my box has packed in so im going to rebuild it would like to know where to get the rebuild kit and torque converter at thanks

 

[RRPhil]

I would recommend that you get the seal/gasket kit, and your torque converter re-manufactured, at an authorised ZF car parts centre. I don’t think there are any in N. Ireland but there are seven in GB :

http://www.zf.com/eu/content/en/gre...twork_uk/service_cars_uk/service_cars_uk.html

I personally use JPAT, but I’m sure that they’re all okay. Clearly you might want to wait until you have your transmission apart before ordering anything as you don’t yet know what additional parts you might need.

Phil

 

[NikP]

So just how difficult is this transmission to disassemble and re-assemble? I'm having some troubles with mine (in fact I think you responded to my post the other day on transmission vs. transfer case questions).

I've recently rebuilt a GM 4l60e with my brother-in-law and was curious if the ZF requires much in the way of special tools and such.

 

[RRPhil]

I find the ZF transmissions much easier to rebuild than GM ones – principally because the ZF clutch piston seals are simple O-rings which allow the pistons to be installed into their drums without the use of any special tools to compress/protect them from damage. As long as you have some Torx drivers (T27, T30 & T40) in your toolkit then the only ‘special’ tools you need are something :

a) to extract the two jump tubes that feed the C & D clutches :

b) to compress the clutch springs

You also need a standard dti to check the front and rear endfloat:

I’m never quite sure whether I’m doing the right thing encouraging people to strip down their transmissions. Sure, they’re very easy to rebuild, and having done dozens of these I know immediately when something’s not right but there’s a risk that an individual stripping a transmission for the first time - unless the fault is obvious like a failed seal or damaged bearing - will end up with a completely disassembled transmission sat on their workbench and no clue whatsoever as to what to do next (though I’m not saying that applies in your case if you already have some experience of rebuilding automatic transmissions).

Phil

 

[rgrimes]

I have a 2005 RR with the ZF 5HP24. It reves up from a dead stop after it warms up. Cluncks going into second. The manual shift doesnt seem t work either... You can nurse it off the line and keep it from clunking and it performs great in the rest of the gears.... I am fluent in everything under thehood but have no trans experience... Coulld you lend some guiedance or a starting point for diagnosis please?
Thanks
Richard [email protected]

 

[saint.v8]

I have a 2005 RR with the ZF 5HP24. It reves up from a dead stop after it warms up. Cluncks going into second. The manual shift doesnt seem t work either... You can nurse it off the line and keep it from clunking and it performs great in the rest of the gears.... I am fluent in everything under thehood but have no trans experience... Coulld you lend some guiedance or a starting point for diagnosis please?
Thanks
Richard [email protected]

My 2003 4.4 is misbehaving at the moment too....I have done plenty of reading and research on the 5HP24 - and RRPhil is the ultimate guru on these boxes....

This link is to an epic thread, makes good reading and no doubt you will pick up some pointers.... http://www.rangerovers.net/forum/6-...4-v8-transmission-problems-failsafe-mode.html

 

[torqueni]

phill i have the gear box all stripped down all seals and bearing all seem in good shape my next step is to take the clucth plates out of a,b,c,d,e but i would like to know is the oil pump in the box hard to strip because i have all the t27s out and it will not pull apart i seen it strip on here i think but cannot fined it again sorry for being a pain phill

 

[RRPhil]

If you remove the ten screws and then screw two of them back in, approximately 180 degrees apart (say the screws in positions 1 & 6 in the second photo), just by a few threads and the tap them alternately with a mallet/hammer it will drive the pump housing slowly out.

Phil