Trans Issue...

[91turbogsx]

A few days ago I had the trans in the '08 just give up under light acceleration and lose everything but park. It wasn't slipping or anything. It just released and free revved. Its a RDP Comp trans about a year old with Suncoast HD converter, billet L/R hub, and billet input. I assumed it was the intermediate as did the guys at Rudy's. Needless to say I pulled it all apart tonight and the intermediate is intact. I noticed nothing else broken or out of the ordinary so far. Curious if you guys know of anywhere else to look? The driveline was fine. Kind of scratching my head on this one after tearing it apart. Was hoping it was just a broken intermediate and all would be well. LOL

Doesn't look broken to me...

 

[MINK]

How do all the clutches look?

 

[91turbogsx]

Fluid was fine. Doesn't smell burnt. Haven't really inspected the clutches to closely but they appeared fine from what I saw.

 

[kyle43335]

Fluid was fine. Doesn't smell burnt. Haven't really inspected the clutches to closely but they appeared fine from what I saw.

look down into the converter. see if the splines for the input shaft are stripped?

ive seen that twice already

 

[MINK]

Mine reved on me out of nowhere, pulled it apart to find just the forwards smoked. If all the shafts are fine then that would be your next move with the trans apart. Just throwing it out there.


edit: mine also did not show burnt fluid, looked and smelled new.

 

[91turbogsx]

look down into the converter. see if the splines for the input shaft are stripped?

ive seen that twice already

I haven't drained all the fluid out of it yet to actually see inside it but I did put the input shaft into it and it feels fine.

 

[91turbogsx]

Mine reved on me out of nowhere, pulled it apart to find just the forwards smoked. If all the shafts are fine then that would be your next move with the trans apart. Just throwing it out there.


edit: mine also did not show burnt fluid, looked and smelled new.

I've yet to pull apart the sub assemblies but that'll probably be my next step to inspect the clutches.

 

[kyle43335]

I haven't drained all the fluid out of it yet to actually see inside it but I did put the input shaft into it and it feels fine.

the shaft wont show signs of anything. the shaft is harder than the hub

 

[91turbogsx]

the shaft wont show signs of anything. the shaft is harder than the hub

Right but what I'm saying is that when I inserted it into the converter it didn't feel like the splines were stripped inside the converter as I tried spinning it.

 

[kyle43335]

Right but what I'm saying is that when I inserted it into the converter it didn't feel like the splines were stripped inside the converter as I tried spinning it.

the ones that i had at the shop felt fine to. its only a few minutes to look.

 

[bigrpowr]

converter took a dump.

 

[91turbogsx]

the ones that i had at the shop felt fine to. its only a few minutes to look.

I will definitely look at that next and I appreciate the advice. I just haven't drained it yet so haven't gotten to physically see it.

 

[91turbogsx]

I have a billet intermediate on the way regardless since I'll be making more power in the spring.

So if it was the converter should I try to get Suncoast to replace it? How are they to deal with when it comes to warranties? Or do I just get another converter altogether?

 

[bigrpowr]

I have a billet intermediate on the way regardless since I'll be making more power in the spring.

So if it was the converter should I try to get Suncoast to replace it? How are they to deal with when it comes to warranties? Or do I just get another converter altogether?

not bad, depends on age for warranty or refresh. i think a refresh is $400 or so..

 

[91turbogsx]

not bad, depends on age for warranty or refresh. i think a refresh is $400 or so..

It's been in for about a 14 months.

Now I have a couple places to look into. Thanks guys.

 

[91turbogsx]

I had someone else mention line pressure. Anyone ever see a loss of line pressure cause the issue i'm describing?

 

[Big Angry Hillbilly]

No line pressure = no clutches applied.

With the converter laying stud side down on the bench, drop the shaft into the centre, but then lift up slightly and see if it spins freely.

This was an inherent problem with the 4F50N, but it didn't always show up because the last couple MM in the stator aren't actually used, and when it's flat on the bench the shaft can bottom out in the converter and appears fine. Lifting it up a little while trying to turn it usually revealed the stripped splines.

 

[bigrpowr]

No line pressure = no clutches applied.

With the converter laying stud side down on the bench, drop the shaft into the centre, but then lift up slightly and see if it spins freely.

This was an inherent problem with the 4F50N, but it didn't always show up because the last couple MM in the stator aren't actually used, and when it's flat on the bench the shaft can bottom out in the converter and appears fine. Lifting it up a little while trying to turn it usually revealed the stripped splines.

line pressure can also affected by a pump failure correct? i know very little about trans diagnosis but i have had a ton of failures.

 

[91turbogsx]

line pressure can also affected by a pump failure correct? i know very little about trans diagnosis but i have had a ton of failures.

I would assume so since that is what makes the pressure. But I'm curious if a bad solenoid or something could somehow create this situation?

 

[bigrpowr]

I would assume so since that is what makes the pressure. But I'm curious if a bad solenoid or something could somehow create this situation?

im pretty sure from experience, that if you lose forward and reverse, which i have had happen multiple times, its converter, or direct clutches. that assuming all shafts are in tact. dropping the pan will , i believe tell you if the clutches are smoked. i know corbin had the hub rip out of his dpc converter and he lost everything.