Great Sonnax 4L60E guides and some other random tips

If you are looking to get your 4L60E rebuilt (or even do it yourself), Sonnax has just published a FANTASTIC set of guides to help you build a bulletproof 4L60E for your application.

Sonnax 4L60E build guide

Level 1 Option B is your best bet for relatively stock cars.  I'd add the heavy duty 2-3 shift valve if you can swing it. If you tow at high speeds with stock rear axle ratio, add the 4th gear super hold servo.  Otherwise, the more Sonnax valves you can put in the valvebody, the longer and more consistent shifting your transmission will be.  

ALWAYS ALWAYS ALWAYS have all bushings replaced whenever you rebuild or have your 4L60E rebuilt.  If you don't, you are throwing away money.  And use every upgraded bushing available.  They're cheap and significantly improve durability.

BTW here's a real handy dandy valvebody identification guide.  

If you're not looking to rebuild your own transmission, I'd also strongly recommend Jasper rebuilds for anything close to stock.  I have had nothing but success both personally and with everyone I know who's put one of their transmissions in any vehicle.  They also closely work with Sonnax to eliminate trouble areas in transmissions.  I've also had nothing but trouble with local shop rebuilds. Unfortunately Jasper doesn't offer rebuilds for every vehicle but if they do for yours, I'd strongly strongly consider it.  Their 3yr/100k warranty is good at any Jasper shop in the nation so it doesn't matter if it breaks 350 miles from home like one of my local shop rebuilds did.

Finally, if you have a '94 or '95 transmission, sooner or later you will lose reverse due to a design flaw that they fixed in '96 with a vented manual valve.  The solution is to go to a junkyard and get any '96-up manual valve, swap it in for yours, but before you put the new valve in, carefully drill two 1/8" vent holes in the vent location on the '96-01 valvebody.  Make sure you get all the chips out before you put the new manual valve in.

Hope this helps somebody out there.

Random add-on: just found Sonnax parts in stock at Rock Auto at great prices. They are not catalogued by vehicle so you'll need to go to Sonnax's website, look up the part number and then search Rock Auto's part number search tool to find them... but Rock Auto carrying Sonnax parts is a great thing.

Great info! Thanks for sharing. There's so much info out there on 4L60e, it becomes paralyzing. Sonnax does a good job of presenting what u need to know

Yeah lots of different chefs have different recipes. Sonnax definitely knows what they're doing and they get down to the root causes of issues and solve them correctly the first time.

I'm working on Chrysler 41TE / A604 transmissions now and the amount of information available on the internet is nowhere near what's available for the 4L60E family of transmissions.

Your posts on the 4L60 stuff helped the most recent rebuilt on Shammoo. It is finally among the living again.

Thanks Joel!