48RE won't go

Yesterday My wife was driving and and the truck just acted like it went into neutral. I went out with trans fluid figuring she had leaked some and just needed topped off. When I checked the fluid in neutral and it was high. My first suspicion was the pump. Thinking that it was a sure thing it had to either be the pump it's self or the torque converter snout I pulled the trans. Pump looks great torque converter looks fine. Now I am wondering if it could just be a clogged filter. The only thing that is keeping me from putting everything back together and changing the filter is the fact that it stopped working so suddenly. I would think that a clogged filter would cause gradual problems. I pulled the input shaft and it's fine. The trans was holding in park so the output is fine. Intermediate is ok.

If anyone has any Ideas what could cause this please let me know. The only thing that would make me more mad than pulling the trans when it only needing a filter is putting it back in with a new filter and still having the same problem.

Normally when they have enough material to suck a filter up, there is another reason. Also a clogged filter will normally move a little after you let them settle.

I found what looks like some pretty serious check ball wear. This one check ball has the separator plate worn so bad that the opposite side of the plate is deformed. I am getting my brothers 48re manual today so we will see if it tells me anything about what this check ball does.

Interesting find.

I’d agree that a plugged filter would be more of a gradual issue. And if your shafts are good, you’re left with fluid flow to diagnose. I have my original separater plate from my 48re if you need one.

I am looking at doing the transgo shift kit while I have it apart. It has a new plate so I should be good. I appreciate the offer though!

That’s forward feed.. that check ball doesn’t need to be in there... it feeds slower with check ball... it’s for smooth drive engagement.. don’t use any steel check balls in the valvebody... ruins everything

Did you read psi before pull the trans in the accumulator port by chance... can you post pictures or pm me your number and send me some pictures of it I’ll look through them... being high on the stick is indicator of not pumping like you stated... either a big leak or pump it screwed..

WPDiesel said:

don’t use any steel check balls in the valvebody... ruins everything

Click to expand...

Can you elaborate?

If you are not to use steel, what is an alternative?

so factory wants smooth engagement... so a check ball is inputted in that circuit to slow apply pressure but they want it to come off fast when the fluid pressure is taken away the check ball falls back and allows fluid to come off faster.. the regular factory plastic check ball. I have a pile of them, if you have any local transmission shops around im sure they would as well. The steel balls beat the hell out of the castings and plates.. The only steel ball I use is the little guy on the back side of the mid plate and OD/Lock up section...

So I originally I had just yanked the trans without testing anything. Stupid move that I regretted very quickly. I got it back together and back in the other day. Still same symptoms. This time I checked pressures. 50 in drive at idle and 200 in reverse. A reputable trans shop said I most likely have a stripped spline somewhere. So back out it came and double checked shafts. I can't find any splines that look stripped, Including the turbine splines. I was able to move the input shaft in the drum just the tiniest bit. My brother seemed to think it may be bad but I can't see how that wouldn't even spin the tires with the truck off the ground.
My next question is, Has anyone ever had a turbine hub failure? My converter is a stock converter with a cut stator and billet cover that I bought outright from pats converters, so I don't have any history on the unit. I have other converters that I could put in but I can't stand how loose they are so that would mean changing it again if that is even the problem. I'm debating sticking this thing in the lathe and cutting it appart.


Talk about depressing, Looking at the dates and realizing that this thing has been down a month.

I forgot to mention. When I pressed the input shaft out I was able to put it backwards into the drum by hand. I don't know if the shaft is supposed to be a press fit into the splines or if it's just that internal snap ring that requires a press

Is this a 4x4? Seen the Transfer case do this. You had no reverse either? I'm sure you looked at your clutches.. No metal in the pan? LIne pressure or gov pressure?

Turns out it must be the turbine hub or the turbine it's self. I put a reman stock converter in and it works just fine.

If it was the transfer case it wouldn't hold in park which it was doing.

Damn TQ Failure didn't see that coming! That a weird failure? I've never seen that before.

I had wondered about the TC. When I had it apart the first time I put the input shaft down in the TC and it had resistance like it was spinning something so I figured it was probably ok.