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So my new hobby has been reading all forum mentions of 5hp24 issues across all brands. My 1997 had a slippage in 2nd and 3rd at WOT, after the second occurrence in drive cycle the transmission would go into fail safe with a code for gear ratio or something similar. So I put the car up in the air and dropped the pan, the plan was to try a fluid change. The filter was aftermarket so I ordered a ZF factory filter. This let the trans drain awhile. I then decided to embrace the suck and drop the valve body to check the upper body for cracks in the F piston circuit. Valve body actually looked great. While I was down there I looked at the few exposed clutch sets I could see and they looked good distance wise, so I knew there was meat on some of them. Huh, perplexed I looked at the oil pipe above the body for damage, I thinks it’s the b drum feed, and was surprised to see a contact spot, but not a hole. So I pushed it and it moved about 1 mm up into the valve body and seated. So I figured hell, if that was leaking it’d cause 2nd to slip to some degree, so I tapped it in best I could without the factory service tool and reinstalled the valve body. Now the interesting part......
I actually set a torque wrench to 8nm and torqued all the bolts. Then I set it for 6.2nm and torqued the valve body to intermediate bolts, and I’ll say that 60% of them turned at least a half turn. When I’d removed the valve body the outer 5 were much tighter than the inner longer ones. So I filled the trans with fresh pentosin atf1, and took a drive.
The transmission now shifts like butter, so smooth it actually made me smile. The 2-3 shift is now solid, and the 3-4 shift is also improved.
I believe that actually torquing the valve body improved the shifts. Just a thought for anyone who has a tired original transmission.
Last edited by Stephjac; Apr 20, 2021 at 09:37 AM.
Well done and glad you had a go. I’ve been inside the transmission too and it’s not for the faint hearted!
One thing to also look at is the Transgo PR valve upgrade. It puts the odds in your favour to avoid the usual A Drum failure esp. as you sound like quite an enthusiastic driver.
And you may want to do this when you do a second ATF change (as the Torque converter holds a lot of old ATF fluid.)
The 'A' drum issue was recognised by ZF, who introduced an updated part in response. Failures of the upgraded drum were attributed to the main pressure valve, prompting a further updated part (see attached TSB), which is an alternative to the Transgo part.
There is also anecdotal evidence that the valve problem may cause the valve body to crack:
The Transgo offering doesn't promise immunity from failure, just a reduced risk of its occurrence. I did this change, following the excellent tutorial posted by BobRoy together with extra tips from DonB: https://www.jaguarforums.com/forum/x...2/#post1648275
You need to do the drain/fill at least twice to dilute the oil fluid that remains in the torque convertor, and I recommend that you stick with the OEM (Filtran) replacement filter. Note also the specific VB torque figures emphasised in TSB 307-03 (also attached) on reassembly.
Adds 1-2 hours to the drain/filter replace/fill procedure.
The OEM filter, pan gasket and 'O' ring can be sourced from a Landrover dealership for rather less $$$ than Jaguar will charge you:
O-ring = p/n TYX 000100
Filter = p/n LPW 000030
Gasket = p/n TYF 000110
Finally - unless someone has been there before, the transmission pan bolts are T27 torx. T25 drive is more common, but might give you grief by stripping out the heads. Give the bolts a good squirt of penetrating oil a day or three before doing the job.
Last edited by michaelh; Apr 23, 2021 at 07:09 PM.
The ZF5HP24 is a common unit, and I put the upgrade "Transgo PR valve" when I serviced the ATF fluid as I had gear slippages, when hot, between 5th and 4th. It seemed like an excellent opportunity to putt in the Transgo PR valve.
It was my first experience inside an auto valve body and I was initially scared that bits would pop out but thankfully it went as per BobRoy's excellent tutorial. Since then, 15,000km later, I've had no issues and the auto gear box is behaving itself.
I know some people with BMWs who also put it in their ZF gearboxes, and they too had no issues with it. There is lots of youtube videos on it. ie for a Home DIY fix on the ZF5HP19 unit see below.
1997 5hp24 findings and actions....FLUID
