C-6 transmission

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Mar 13, 2000 | 10:09 PM

JerseyBronco

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C-6 transmission

Folks

I could really use your help with this one folks
I have auto C-6 tranny in a 86 with a 351W 4bbl 4x4
The problem is this as I drive I have to let up on the gas for the tranny to shift into gear the guys at the tranny shops tell me it's shifting 1st into 3rd and that the tranny needs to be replaced with a "new rebuilt" tranny
Does anyone of an easier or cheaper fix and if I do need a new tranny does anyone now of a where I could get one cheaper

Thanks

Mar 14, 2000 | 06:43 AM

big60

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C-6 transmission

The C-6 tranny is a very durable beast. The vacuum modulator is a small device on the back of the main body of that tranny. It will fail with age and cause shifting problems. It has a vacuum line running to it; if you pull that vacuum line off and transmission fluid drips out, then you better replace it because the diaphragm inside is probably ruptured. They are cheap, about 20 bucks.
I would also drain all tranny fluid (converter included) and change the filter. I would try these things and see if it improves.

Mar 14, 2000 | 07:27 AM

Nathan

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C-6 transmission

Also, check to make sure the passing gear linkage from the carb to tranny is working through it full range of motion. Sometimes they will stick at one pivot point.

Nathan

Mar 15, 2000 | 09:33 PM

JerseyBronco

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C-6 transmission

Thanks Gents for your help and suggestions

A brief update on some of the things you folks suggested; the vacuum line was removed and there was vacuum to the trans and the linkage was also looked at and in working order according to the tranny shop, they said they would have to look inside the trans for further evaluation.

What do you folks think about that does that sound about right to you folks
Unfortunately I'm not much of a trans expert

Mar 16, 2000 | 04:21 PM

Nathan

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C-6 transmission

I would check out the above possibilities myself to confirm. Tranny shops are in the business to rebuild trannies, and some are not very ethical in their diagnosis. I had my C6 serviced at a shop once and they told me I was in desperate need of a rebuild. I told them to just finish the service that i asked for. My C6 went 60,000 miles after that before I had "another" shop rebuild it. I hate to point a finger, but it happens way too often. If you dont feel comfortable checking yourself, get a second opinion from a shop with good referals. Good luck!

Nathan

Mar 18, 2000 | 11:25 AM

Katt

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C-6 transmission

It takes a lot to kill a C6. I doubt you need a rebuild just yet, and definatly not a new tranny. If you did, I saw a C6 for sale on the classifed section of this site a few weeks ago.
Good luck

Mar 21, 2000 | 09:49 AM

Chuckybaby

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C-6 transmission

I'm with big60 on this one... I had a chevy econobox that would go from 1st to 3rd...replaced the vacuum modulator (after the local tranny shop advised a $700 rebuild) and it cured the trb.