Just wanted to post this to see if anyone has had a similar issue and knows exactly where to start, I have recieved some good info from reputable builders but I hope to go straight to the source here's the issue.
2 months ago I bought a sonnax 4th gear hold and transgo hd2 kit I installed the sonnax and the parts for the servo, well I didn't seat the sonnax correct and I drove a short distance before my trans let go of the gear... I slowed down then tried to take off again 1-2 sliped and 2-3 made a grinding noise. I stopped and looked underneath to discover the sonnax was gone and I left a trail of fluid down my street. I pulled the truck home, the servo were bound onside the bore by the seals I popes them loose and used a new seals, from that point I have had a 2-3 shift flare like the band release and the clutches stall before grabbing, so I went ahead and installed what I could of the transgo in the valve body to spec I took off for a drive and it still flares. Tow haul helps but really light throttle and low line pressure it's not happy... I drove it like this for 3 weeks before I lost 2 and 4 I removed the trans and rebuilt it to specs and added some standard upgrades. Only issue was the band and drum were both burnt up everything else in the 120k mile trans was in great shape. After the rebuild I drive it guess what's still present the 2-3 flare at this point I'm at a loss I reset the computer tried everything and it's present daily full throttle it's fine and tow haul helps. So does anyone have a idea exactly what's up?

 

I will also add, it doesn't do the kick down procedure correct it seems to confuse it's self, unless I manually pull it down, also it will feel sluggish on cold mornings and 4th gear will come on at 40mph and turn 1100 Rpms don't know if any of this is helpful just thought I would add

 

Sounds to me like its screwed and you need a rebuild, the sorry shifts and the grinding when it shifts would settle it for me.

 

Not to be rude but did you even read the whole post? It was rebuilt 3 weeks after the initial incident.

 

ANYONE looks like Ill be pulling the trans to go inside it I was hoping maybe it was somthing simple to look for.

 

so did you replace the 3-4 clutch pack? One some transmission I have done, then clutcehs all have material, and are not burnt, but the overall clearance is .100 or more..this will cause a fair...to much 3-4 clutch cleanance. Get the raybestos 3-4 clutch pack, they have always worked good for me in my 500rwhp builds...out of the box clearance usually is .060, but some builders like it in the .030-.040 range

 

Have you preformed a pressure test to see if you are loosing pressure when this happens? Also have you tried to do this?http://www.sonnax.com/system/pdfs/13...pdf?1289926276