Has anyone done this valve mod on the ZF 5HP24 transmission? I saw it mentioned on the AULRO forum.

https://transgo.com/product-details/zf5hp-...or-repair/

Their website says:

Quote:

Simple fix with no reaming or special tools required
Installing the ZF5HP-24 Pressure Regulator Repair kit is a simple fix with no reaming and does not require special tools or complete disassembly of the valve body. This Pressure Regulator Repair kit fixes the PR valve malfunction that causes rough or bangy shifts complaints. If you need to disassemble this type of valve body, exercise a great deal of care when removing the separator plate from the upper channel plate as this is where all the small parts are located. Make note of where the small parts go because they are different for each model.

Corrects/Prevents/Reduces:
Runaway pressure that breaks drums
Harsh shifts
Kick-down bang

Quote:

Just installed the TransGo Pressure Regulator fix for my 05 L322 w/ the ZF5HP24 trans + fluid change and OE Filter.

Have to say she's smooth as butter now. Do recommend for around 100 AUD landed from the US.

TransGo | 5HP-24-PR | ZF5HP-24 Pressure Regulator Repair Kit

Happy to answer any questions about the install if anyone is/has wondered about doing this.

Pressure spikes from a worn pressure regulator valve bore I have been told is the top cause for failure (A drum), that and heat.

I must admit than I’m not a particular fan of the TransGo main pressure valve for the 5HP24. I don’t think that the spool bores wear evenly enough for the stiff sealing rings (with scarf joints) to conform accurately to the worn shape and I’m also concerned that the wear extents are sometimes very sharp and the seals have to ride over these sharp edges.

The kit comes with a couple of O-rings that you initially roll over the two sealing rings to compress them into their grooves to facilitate installation, but I find this a pain. I should emphasize that this is just my personal opinion, and I’m sure a lot of people swear by them.

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Phil,

Thank you for your excellent reply. I wish you were Down Under!

I think I'll contact the auto transmission workshop which rebuilt mine (for the previous owner) and ask if they did any work on the valvle block, e.g., replacing that valve and reaming the bore.

Fortunately, the workshop does all the auto trans work for the Landie independent workshop I occasionally work for so I have an in there.

Reaming looks to be the way to go. Ron B. VK2OTC
2004 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

Now that is what I would call a comprehensive response.... Current:
- 2013 L405 4.4 TDV8 Vogue
Sold:
- 2004 L322 4.4 Vogue (BRC LPG)
- 2002 L322 4.4 HSE (having fixed timing chain guides)
- 2000 P38 4.6 Vogue (BRC LPG)
- 1981 2-door In-Vogue
- 1980 Ex-Army SIII LWB
- 1976 SIII LWB
- 1968 SIIA
Stripped for parts:
- 2003 L322 4.4 Vogue