I have had a suncoast stg 3 in my truck for a little over a month or so. It has always dropped in to 5th gear hard (kind of a clunk). I figured it was because it was built and havn't thought anything of it.
I have the 1057 converter and it feels like its starting to lug pretty good in 5th at around 50mph. Its almost like its slipping a little. I am kinda lost to explain it.
It also feels like its slipping on startoff in 1st (it is- don't have the power off the line- lack of smoke too). I am running the preditor at 100hp. But thats within the range of the tranny - any ideas?
Anybody have any ideas. It runs hotter than the stock trans did. I don't know if that means anything (still within standard range).

Kinda lost here- thanks for the help.

How's your fuel filter?

I think alot of the tranny shifting problems, lugging, and defueling is in the tuning. I have been fighting this problem for a long time. I have changed over to a 01 OS TCM (about 6 months ago). I have reset the taps probably 6 times. Changed the fuel filter and tranny filter probably 4 times each in the last 4000 miles. I am tired of battling this problem. I am thinking of returning to stock tuning because the current setup has been frustrating.

I just got a SC3 a couple of months ago also ! I bumped my Pred. up to 100 and have not really been all that happy with the way the truck runs.......except at WOT !!

Last week I switched to the 85 tune......and while I don't like going backwards in power.......my truck runs a lot smoother and shifts a lot better ! I love the way the 85 tune drives......would love a big tune that had the same characteristics !!

I still feel the convertor lock up after the 5th shift........but the trans. guy said it would be noticable when I got the install done !!

fyi my ppe shifts alot better then my predater ever did.

I used to run a PPE Hot +2 until I went to some custom EFI live tuning. I found the PPE shifts alright but didn't like all the smoke. Now I have less smoke but real poor shifting / surging. Can't seem to win.

I run a suncoast III and Kennedy's tow/performance tune and the truck is perfect all the way around. Most programmers/boxes have their issues, EFI tuning from someone who knows what their doing will make all the difference.

How's your fuel filter?

Seems fine, I am going to get a new one and replace it to be sure but I am showing just over 50% left on the DIC.

I might try to drop the tuner down to 85 just to see if that does anything, but it doesn't feel like a tuning problem. In other words it hasn't done this until Friday evening. Been running pretty good up until then.

I run a suncoast III and Kennedy's tow/performance tune and the truck is perfect all the way around. Most programmers/boxes have their issues, EFI tuning from someone who knows what their doing will make all the difference.

I have really considered doing that myself. (gonna finish paying off the trans job first- seeing how it wasn't really a planned job in the first place)).

Wpatrus,
You might want to remove the programer to see how she runs without it. My SCIII shifted exactly like the stock unit when my truck was stock. Shifts with the KD tune and SC are same as stock. Only difference is the truck is faster.

How is it in TH mode?

My definition of lugging is low RPM lazy and the RPMS don't come up. This would be contrary to the notion of slipping. The gear positions can also be quite confusing. At around 50mph or so you should feel the TCC engage.

Put a tech 2 on it and check turbine speed sensor against input speed sensor in first gear. They should be very close, if turbine speed is a lot lower, you have a draggy converter clutch or a sticking converter flow valve or partialy plugged cooler.

How is it in TH mode?

My definition of lugging is low RPM lazy and the RPMS don't come up. This would be contrary to the notion of slipping. The gear positions can also be quite confusing. At around 50mph or so you should feel the TCC engage.

I will check this in an hour or two. I haven't really ran it in tow haul in the past few days since it's acted up. It is feeling a lot like it did (and having simuliar problems) before I got the trans fixed.


I don't have a tech two- but will get the shop that did the job to look at it when I take it back down that way. Been a busy few days and the weekend. THe shop should have the equipment.

THanks, for all of you help I am gonna take off the tuner before I go anywhere else to see it thats has something to do with it.

I checked the tow haul mode and it seems to do ok. Of course that was after I took the tune off. At stock it drove fine didn't see any real problems with shifting. I bumped it back up to the 85 tune today and the same, I can't see any real problem with the shifting.

Anybody think its just the tune (preditor 120hp/250tq) or is it just showing the trans problem at that power level. Of course it ran ok today on the 85 tune- but the ambiant temprature is cooler outside than it has been in past week or two (rain thank god-just need more).

I will run the 85 for a while to see if the problem presents itself here as well untile then any more ideas? I haven't been able to check the input and output shaft RPMs like Mike said- but anything else anybody can think of until I have that opportunity>?

Thanks again,
Walt

I think it's the big tune .....like I said........the 85 tune runs a whole lot better on my truck for everyday driving !!

So does TH seem to take care of the problem?

It seems too, I will bump it back up to the 100 and run solely in tow haul and see if if duplicates it.

I think you may be feeling the TC lock. Mine is very hard in 5 at 45-50 mph almost feels like a hard gear change. It shifts great in TH as the Convertrer is locked. I have tried adjusting the fuel at TC lock but it is still a hard lock up.

I think you may be feeling the TC lock. Mine is very hard in 5 at 45-50 mph almost feels like a hard gear change. It shifts great in TH as the Convertrer is locked. I have tried adjusting the fuel at TC lock but it is still a hard lock up.

It's not that, I have felt that and know that one. It hasn't done this since install (only a week or so).

It was hesitating a little today and I had a chance to take it to the shop. He wants me to verify its not the fuel filter first and bring it back tomorrow so we can road test it with the tech2. I know you guys mentioned the filter earlier but I didn't think it would be a problem (46% left). But we will rule that out first. I want him to check it on the tech 2 anyway just to see if anything pops up.
Will let you know what we find.

When diagnosing a problem, never refer to the information center to eliminate things to check. That is a big waste of time for everybody.

It shifts alot better than it did, but still hesitates slightly just at take off at full throttle. I think that might be because I am using stock fueling and maybe its just runnig a little dry at full throttle at take off. Thanks for the help though.

My truck did that 2 after tranny job The stock tranny was holding my truck back quite a bit 1 noticeable diff was boost my truck went from 22 at wot to 28 to 30 I bought the super diesel lift pump and works like a charm.

After driving a few days its still acting up. We have ruled out the fuel filter.

Its not slipping - but lugging mostly in 1st gear when you first give it some gas. I can punch it and it hesitates and creeps up for a few seconds then the power kicks in. But it doesn't feel like its all getting to the ground.

I really have no idea if this is the trans doing this or the fueling. I am taking it to the shop tomorrow after work and hopefully he can go out for a test drive with the tech2 tool.

Anybody have any ideas. Maybe a shim mod? Is this whats thats for.

Thanks again and sorry to drag this thing out...

I would say it is the amount of fuel / boost being delivered at low rpm until the turbo spools up. I would look more at the tune being the culprit of this. I am going through some tranny issues for about a year with the same type of symptoms. Everything I have tried has not worked. I will know shortly if it is the tuning.

I would say it is the amount of fuel / boost being delivered at low rpm until the turbo spools up. I would look more at the tune being the culprit of this. I am going through some tranny issues for about a year with the same type of symptoms. Everything I have tried has not worked. I will know shortly if it is the tuning.

I thought that also. I also found simular issues mentioned in the lly section in a post about hesitation by "Renike" (sp?)...

Might be something tied to a leeking EGR Blocker plate. I am going to check this at the next opportunity. (tomorrow evening or saturday Morning).

Thanks though I am afraid you may be right and that sucks. (guess time to fork it up and get the EFI I am thinking).
Walt

A little update...

I took out my EGR blocker plate, cleaned and reinstalled it. I had been looking at it the past few days and noticed what appeared to be bubbles of soot that would occaionally come out the top.

After reinstalling this and being sure to torque it down as best as I can it is driving and reacting a lot better. All I can figure is the slight leak caused a loss in presure that hindered performance til it got spooled up.

It felt like a trans lugging at first and I figured that to be the case since it had just been installed. Instead it seems the increased presure and power caused this part to fail...

Thanks for you help with this and maybe this can help shed some light on someone elses problem.