4l60e dragging 3-4 clutch discs

**driver99** · 05-29-2009, 04:41 PM

My wife recently purchased a 99 z28 that apparently has trans issues. It has, and currently is in, been in and out of a performance shop on the island. The trans, I am told, has been completely gone through and nothing seems to be out of sorts. It is currently on its 3rd set of clutch discs in the past 6 months. It seems to be dragging these somehow. As if they are constantly engaged i suppose.

I haven't seen personally as I am deployed in Iraq. But the shop its in can't seem to find the problem so I was wondering if there were any thoughts on the issue- maybe common problem for this trans?

It has 90,000 miles on it and is driven responsibly. Line pressure is good, it throws no error codes, shift selenoids have been replaced, and new valve body has been installed. This mechanic is simply throwing parts at it i think- i need to know whats up.

Thanks

**driver99** · 05-29-2009, 04:42 PM

its dragging th 3-4 discs

**Cutlass** · 05-29-2009, 05:25 PM

I've replaced input housing for multiple comeback 3-4 clutch pack problems. Seems to fix them. Another option is to just get a whole different transmission and move away from this unfixable nightmare

**fieropope** · 05-29-2009, 09:19 PM

the shaft that goes into the input drum(input shaft),can become loose over time and givin the fact that the 3-4 clutches are applied through the holes in this shaft any leakage of apply oil will cause the clutches to apply "softly" and if its bad enough burn the 3-4's in as little as 50 miles especialy with some power behind it ,you could also check 3-4 accumulator piston for wear around the pin which will also leak apply oil and burn the clutches,lastly if the input drum is worn around the input shaft the endplay for the clutch packs can b out of spec. and drag the clutches as your saying also burning them , those are the only things ive heard of to cause this symptom, as long as all the seals in the drum are installed correctly. hope this helps ,

Dakota

**900HPBIRD** · 05-30-2009, 07:18 AM

They are not dragging,they are losing pressure and slipping. Better have that input drum checked out for a loose input shaft like fieropope said. The shop needs to put a mechanical pressure gauge on it also to make sure the pressure rise is doing what it is suppose to.

**fieropope** · 05-30-2009, 05:58 PM

he is the transmission physician for god sake what he says is almost 95% right ( not sucking up or any thing)

**Bigdaddy** · 05-30-2009, 06:08 PM

Would my SS with 32k have the same issue. I was told it was slipping a lilbit on the dyno during tune.

**fieropope** · 05-31-2009, 07:53 PM

there's quite a few things that can cause a slip those are just a few things ive seen burn the 3-4 clutches after a rebuild when it wasnt checked thoroughly, but the best way to know is for us to test drive it.you hve a pm