This is for anyone who has had a 700R-4 fail. My question is what gear failed first?

 

Had one lose fourth, a few miles later lost third and second, it was a stripped governor gear.
Never had any other problems.
Usually it's the third/fourth clutch pack. I have seen a few cores with stripped out forward clutch splines.

 

just wondering mine seems to be slipping in 3rd now

 

It's probably the clutch pack. I have a rebuilt 1990 700R4 that has a few mods, no kit. It slipped at full power 2-3 shifts. I changed the 3-4 clutch stack clearance from stock specs (.049-.113) mine was .089, I tightened it down to the transgo recommended .035, it doesn't slip now, even with an estimated 360 HP.
You'd be better off with a rebuild at this point (depending on mileage). If it gets rebuilt make sure the clearances are not set to factory specs.

 

Some years ago I did failure analisys on all of the 700's that came into the shop for quite a while and to my surprise I found about an equal distribution of Forward Clutch, 2/4 Band and 3-4 Cltuch failure, not counting hardparts related failures which are normally lube related. I expected to see it more Band or 3-4. I do tend to think on Hi-Po vehicles that we see the 3-4's show up first but the bottom line was that all three of those failures were usually traced to the same thing: Pressure Rise malfunction. The TransGo SK/Reprogramming Kits both address this problem and fix it.

 

Thanks guys. I am going to try and make it last until spring so I can get all of my 6spd stuff together.