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Riffraff Diesel Performance Inc, Engines - Supplies, Equipment & Parts, Eagle Point, OR


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John Wood 4R100 Valve Body

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Part Number:

John Wood 4R100 Valve Body

We offer modified valve bodies from John Wood Automotive because it is our experience that they are one of the best offered in the industry.  John Wood has been building transmissions and valve bodies since 1983 and has a reputation for strong attention to detail, quality before quantity and excellent customer service. 

A JW Valve Body will help to firm up shifting, while keeping the shifts crisp and not banging into gear.  Also performs shorter shift duration, which decreases heat generated and reduces slippage and wear on the friction plates. 

While the valve body can be used with stock programming, we suggest DP-Tuner if you are thinking about upgrading.  Jody and John work closely together to make sure that you will get the most out of your transmission.

Please note that there is a 3 week window for core returns.  If the core isn't recieved back 21 days from customer reciept then your core charge will be forfeited down to 50% and after 30 days you will be charged the core retail cost of $150.

Fitment Details

1994-2003 4R100 Transmission

This part is unable to be returned after received.
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Product Reviews

  1. Like usual great product 5 Star Review

    Posted by on Sep 5th 2016

    Riffraff never lets me down another great product!!!

  2. Great upgrade 5 Star Review

    Posted by on Jun 23rd 2016

    I haven't had a chance to tow with it yet. But just normal driving you can feel the difference in the shift. It's not a long shift anymore. It's fast and smooth.

  3. Great product 5 Star Review

    Posted by on May 31st 2016

    The transmission shifts much quicker without being harsh, an easy project with Riffraff's instructions. As always, great service from Riffraff.

  4. Very well done 5 Star Review

    Posted by on Oct 16th 2015

    It has firmed up the shifts and the transmission seems more responsive.

  5. It Does Make a Difference 4 Star Review

    Posted by on Oct 16th 2015

    I replaced the stock valve body that came on a new 4R100HD with this JW product. The stock VB was very, very smooth and subtle on the new transmission. After this product was installed, I can feel the really quick shifts. It is not harsh, as others have noted, but each shift is felt. So far, so good.

  6. Installed on my 1999 Fleetwood motorhome. 5 Star Review

    Posted by on Oct 14th 2015

    The transmission has 44,000 miles on it but I felt the shifting was too slow and possibly prematurely wearing the clutches. This took out all the slop, firm but not jarring. Easy to install, I just had to get an inch pound torque wrench.

  7. Great valve body 5 Star Review

    Posted by on Sep 25th 2015

    Really smooth shifts still like stock but still shifts quicker than stock valve body

  8. works great, now we'll see if it'll help in the long run 5 Star Review

    Posted by on May 22nd 2015

    Installation was pretty simple. Seems to have firmed up shifts across the board.

  9. AMAZING$! 5 Star Review

    Posted by on Mar 15th 2015

    Great product does as described #1 customer service!

  10. Love it... 5 Star Review

    Posted by on Jun 12th 2014

    The JW valve body did exactly what I wanted it to do. It firmed up the shift points and when it does shift, it quick and precise. Even with a custom chip, it shifted a bit soft(stock like)for my style. I'd say its perfect now!