C6 Tranny Diagnostics

[Miss Kitten]

hey guys i'm hoping there's some C6 experts that might be able to shed some light on the problems that just developed with my tranny

we were on a hard recovery yesterday and after i blew apart my front hub i was left with only 2 wheel drive to get back out of where we were

i was on the gas pretty hard going up a slick hill and there was a log almost at the top of the hill. i came off the gas a bit to slow down for the log, bounced over the log, hit the gas again and there was nothing. no forward gears at all. after i got pulled to the top of the hill i ran through all the gears (reverse and all forward moving gears) in all t-case positions and had nothing

i got towed back the rest of the way and hit a few nasty bumps as i was being pulled. we pulled the bronco onto the trailer with the other truck and took it home

when i got home i found that i had reverse again but still nothing in the forward moving gears

i haven't dropped the pan or anything yet as i still need to clean the truck tonight, but any direction on what to look at or check would be greatly appreciated. i'm very new to the C6 tranny but i have the gut feeling that it's going to have to go in for a full rebuild (or be replaced)

also is there a difference in the C6's btwn small blocks and big blocks?

thanks in advance for any help

 

[Foul Al]

hey guys i'm hoping there's some C6 experts that might be able to shed some light on the problems that just developed with my tranny
we were on a hard recovery yesterday and after i blew apart my front hub i was left with only 2 wheel drive to get back out of where we were

i was on the gas pretty hard going up a slick hill and there was a log almost at the top of the hill. i came off the gas a bit to slow down for the log, bounced over the log, hit the gas again and there was nothing. no forward gears at all. after i got pulled to the top of the hill i ran through all the gears (reverse and all forward moving gears) in all t-case positions and had nothing

i got towed back the rest of the way and hit a few nasty bumps as i was being pulled. we pulled the bronco onto the trailer with the other truck and took it home

when i got home i found that i had reverse again but still nothing in the forward moving gears

i haven't dropped the pan or anything yet as i still need to clean the truck tonight, but any direction on what to look at or check would be greatly appreciated. i'm very new to the C6 tranny but i have the gut feeling that it's going to have to go in for a full rebuild (or be replaced)

also is there a difference in the C6's btwn small blocks and big blocks?

thanks in advance for any help

sounds bad... you might look into getting it flushed first before replacing. if you need a replacement i have one available with 20 or 30 thou. on a rebuild. if you are going to need one p.m. me

 

[Miss Kitten]

thanks al, but i think the shipping from penn might **** me lol

i just got the truck all washed up tonight, so first things first is i'm gonna get the rear diff on the 6 ton jack stands and get the tires off the ground. and then do some playing with the linkage and see if anything hooks up

after then then drop the pan and see if anything goes plink

 

[Justshootme84]

Most problems with the C6 are due to something wrong with the modulator valve. It runs off of engine vacuum. Internally, the C6 is very tough so you shouldn't tear anything up just hopping a log, unless you say hit the pan and all the fluid ran out. The Haynes manual has some tips on diagnostics, or check Miesk5's website, JSM84

 

[Bronc76]

also is there a difference in the C6's btwn small blocks and big blocks?

Small block 5 1/8" top bolt center

Big block 7 11/16" top bolt center

 

[Miss Kitten]

i did some phoning around today to tranny shops and there's one not too far away from me that is going to take a look at the tranny for me

we aren't exactly what's been upgraded on the tranny as far as clutches, valve bottle and TC goes, so if they haven't been done i'm gonna look at upgrading them too

now it's just to get it dropped and work on the rest of the repairs required on the truck too

 

[Justshootme84]

MK, if you're going tobe online tonight, maybe we can chat before you go to that shop, Randy JSM84

 

[Miss Kitten]

oh jsm i would love to chat, but the hubby is at home already prepping the truck to drop the tranny

if i don't get out there to help him he won't be too happy lol

 

[Miss Kitten]

ok so tonights progress revealed a few different things

for starters the design on this truck is freaking horrible. omg we had to take down both sides of the exhaust right at the headers, found out that when they made the tranny cross member it was obviously never expected to have to come out cuz well it won't come out of the frame rails. it was obviously welded in place not thinking of the future.

onto what we did find out. the fluid was burnt. not extreme there was some red in it, but burnt none the less

when we finally dropped the tranny pan we found one bolt in the pan. the bolt wasn't sheared off, and it's from the valve body. it honestly just looks like it worked it's way out.

so now we're wondering if that one bolt coming lose would cause enough of a loss of pressure to stop the forward gears from moving

please post up thoughts on this and if there's a general agreement that that could be the case would it be more worth our while to put the pan back on the truck, reattach the driveshafts and fire the truck up to see if i have forward gears

 

[Justshootme84]

Sounds like a good plan to me. Bolt it back up and test it out if you didn't find any metal shards or excessive dust from the slippage.

 

[Miss Kitten]

so just to make sure jsm you figure it's worth it to bolt everything back up again cuz that one bolt would cause enough pressure loss??

can you come into chat??

 

[Miss Kitten]

wowie i'm a superstar. i blew up an 4r100 forward clutch drum

 

[Justshootme84]

MK, I'll try to catch you in chat, but I'm having login problems.