Transmissions

[Uncle Wally]

Ok guys, the frustration is mounting now.

Half way to work this morn, she stayed in 2nd gear. Limped the rest of the way there and then back home later.

Pulled codes. Got a 39, 87 & 88.

The 88 is something I have been working on with IP Timing, so that one doesn't worry me as much as the trans.

The 39 is a TCC off code. Not sure as to why this one is there, but I figure it will go away when the 87 is gone.

The 87 is a ratio low code. Meaning it is slipping. I still have some work to do in the diagnostic world to make sure the trans isn't toast, but with my recent experiences, it probably is.

???????

I can't afford to pay for a rebuild at this point, so I'm going to have to do it myself. Any suggestions?

I have all the GM Manuals for my truck. I have a means to get all the updates available to the manuals/transmission. Is there any other literature that I should look into before attempting this? I have done several manuals and one auto prior. (the auto didn't work well - but I didn't feel bad as 3 other 'professionals' couldn't figure out the case was cracked on TH2004R either.)

- I know you always use a new converter when rebuilding.
- I also plan on using Amsoil again.
- Flushing the cooler shouldn't be an issue as I plan to use a different trans cooler and larger hand bent stainless lines. (that should increase capicity slightly)
- I already have a deep pan by Hughes Performance.
- I have a digital cam to aid in remembering how things should go back together (they helped immensly when I did a Muncie a couple years ago)
- I am considering a shift kit. Will there be any issues with running higher line pressures as commanded from my TD Max chip?

Any other suggestions from any of you seasoned pro's? The more info, the higher the possibility of success.

When you buy a rebuild kit - is there any particular brand that is better? Or any I should avoid?

I guess this is a good start. I will investigate the codes and any electrical/electronic issues on Monday. In the meantime - feel free to toss in two cents! (it might reduce my expense if I get enough opinions!)

Thanks in advance,
Waldo

[Shad]

If its just the soft parts clutch disks and such my trans guy said its not to expensive, but when you have bad hard parts -drum,cases,shafts thats when it may get expensive. I personally dont work on transmissions because it seems like there are too many specialty tools needed and you need a good eye for damaged/overheated parts also a little piece of debris/dirt left in the rebuild can be a real headache. I leave this to the professionals...Just my two cents

[rjschoolcraft]

I've never done a 4L80E, but I have done several THM350's and some THM400's. They're not that hard if you have the manuals and are experienced at other mechanical work. I found ways around nearly all of the special tools.

Back in my college days when I was doing some low-budget drag racing with a 67 Camaro, I grenaded a 350 turbo. I was able to get a $10 junkyard transmission to acquire most of the necessary "hard parts" and pieced together the other components from another one that I had lying around. Back together in a weekend.

[moondoggie]

Good Day!

I'd do some searching in the forums before taking your truck apart. I remember reading a topic within the last couple weeks or months where someone had a similar problem & it turned out to be dirty and/or failed speed sensors. I think there's two - one each for tranny input & output shaft speeds. If the PCM detects slip, it goes to limp mode.

I get this all the time when I don't use my Gear Vendors right, although it doesn't go to full limp, just max pressure causing hard shifts.

Blessings!

Brian Johnson, #5044

'82 6.2 1500 4X4 1/2T pickup, 4spd man w/ OD, bone stock, 335K+, "In Rust We Trust"
'89 6.2 4X4 1/2T pickup, bone stock, 146K+
'95 6.5TD 2500 4X4 heavy 3/4T pickup, Gear Vendors Aux. OD, 185K +
'95 6.5TD 1500 4X4 3/4T Suburban, Kennedy exhaust, 200K +

[LanceW]

Wally, check here (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=004755) . There are a couple other threads along this same line a little older than this one, too.

[ucdavis]

Wally,
If you are the lucky type, you need to reboot your pcm. Twice mine kicked me into limp mode so I was stuck in 2nd.
Erase codes, ohm-check all grounds using a 10 ohm scale & fix any that register resistance, then disconnect the batteries for ovenight to deny pcm voltage. Reconnect & run the vehicle. Not a high percentage shot (because of the codes you've got; I never got any) but worth the minimal investment.

[Bill Voitel]

watch carrefully your bushing & oil clearances if it bleeds of oil psi it can cause the torque converter not to hold and it will set that code also it will set a 4th gear ratio code in fourth and in 3rd tcc stuck off code, also valve body can have the spool valves worn and bleed off apply psi. hade one of these in our shop 3 times replaced entire valve body been in service now 3 weeks have not seen it back thank God......Bill.

[vernj4]

Originally posted by moondoggie:

I get this all the time when I don't use my Gear Vendors right Brian......

Tell us more.....what is the proper way to use (shift?) the Gear Vendor transmissiion? Also, where did you get yours? was it new?

I plan on adding one but would like to get more familiar with its pros & cons.... Would like to have an indepth discussion about the GV.

Thank You
Vern (vernj4@juno.com)

[Uncle Wally]

Update------------

Cleaned the speed sensor in the t-case - no change.

Fluid level was good, smelled a little burnt, but it's been that way for a while. Did the homemade flush with synthetic when I first got it, it took a month before it had the same burnt smell. that was 25K ago.

Dropped the pan, fluid looked ok. No parts in the bottom of the pan.

Ok - now I looked in my GM manual and I can't seem to figure out which servo is which. I want to find the 3rd gear servo and the reverse servo to look at o rings for those. I am stuck in second gear (due to the code for slippage) and I have no reverse. I am suspecting that there is some mechanical damage inside on some o rings at this point.

Anyone know enough about these to make me more dangerous than I already am?

Waldo