C5 questions

Rulebreaker · Jul 4, 2008

I put a stock C5 in my Broncostar. Upon initial drive it did not shift out of 1st unless you pulled it down into 2nd and then it would shift. Thought the modulator was bad so pulled it out and put another used one in although the replacement had a red stripe on it where as i believe the one i took out was green. Still no up shift so i put a vacuum gage on it and had no vacuum. Fixed problem and now it shifts fine from 1-2 but it slips going from 2-3. Reverse works great. 1-2 and 2-1 work great but 2-3 or 3-2 creates and over rev for about 3/4 to one second. At light throttle it's barely noticeable at WOT it's very noticeable. What is the next step in fixing this? or diagnosing it further?

I run the coolant lines assuming the forward one is outgoing and rear is incoming fluid. Is this right.

I used regular mercron fluid. Is this right? I read in the tech library it takes H but had never even heard of that before.

Thanks RB

Sasquatch_Ryda · Jul 5, 2008

I beleive the c4, c5, c6 all take Ford type F ATF, not to sure if that would make any difference but i thought i'd throw that out there.

projectnitemare · Jul 5, 2008

Mecron will be fine, type F is what was called for in the older transmission but Mercron is fine also. Check your band tension for starters. Tighten to 120 in-lbs and then back off 1 3/4 turns for the intermediate band and 3 turns for the reverse band. See if that helps. If not then your problem is internal. It could be a weak or broken spring in the valve body or damaged lip seal on a piston. Start on the easy fixes and work from there.

Matt

gotmudd · Jul 5, 2008

projectnitemare said:
Mecron will be fine, type F is what was called for in the older transmission but Mercron is fine also. Check your band tension for starters. Tighten to 120 in-lbs and then back off 1 3/4 turns for the intermediate band and 3 turns for the reverse band. See if that helps. If not then your problem is internal. It could be a weak or broken spring in the valve body or damaged lip seal on a piston. Start on the easy fixes and work from there.

Matt

had the same problem happen on an older C6, there is an o-ring inside, i think the tranny shop said it was inside the valve body,and he said that when that o-ring fails it allows pressure to bleed past, creating the slip. not sure if that is your problem or not, mine only started to slip after it had reached opperating temp

Rulebreaker · Jul 5, 2008

projectnitemare said:
Mecron will be fine, type F is what was called for in the older transmission but Mercron is fine also. Check your band tension for starters. Tighten to 120 in-lbs and then back off 1 3/4 turns for the intermediate band and 3 turns for the reverse band. See if that helps. If not then your problem is internal. It could be a weak or broken spring in the valve body or damaged lip seal on a piston. Start on the easy fixes and work from there.

Matt

I followed the band tension directions in this. http://www.therangerstation.com/tech_library/C5Diagnosis.html with no change but it says 4.25 turnes. RB

Totalled · Jul 5, 2008

If you're running a stock 2.8L C5 valve body and servo behind a 4.0 I'm not surprised. You need a V8 C4 valve body with a shift kit and at least an "A" servo if you expect it to take a 4.0...

Rulebreaker · Jul 5, 2008

Totalled said:
If you're running a stock 2.8L C5 valve body and servo behind a 4.0 I'm not surprised. You need a V8 C4 valve body with a shift kit and at least an "A" servo if you expect it to take a 4.0...

Something like this? http://store.summitracing.com/partdetail.asp?autofilter=1&part=TCI%2D522100&N=700+4294880856+4294908331+4294905612+115&autoview=sku

Rulebreaker · Jul 5, 2008

And this? http://store.summitracing.com/partdetail.asp?autofilter=1&part=TCI%2D523005&N=700+4294843763+4294851527+4294905612+115&autoview=sku

Bruce · Jul 5, 2008

You didnt loose the little pin that goes between modulator and the valve inside did ya??

Only thing applied in 3rd gear is forward clutches and direct clutches. Could possibly be the little check ball in the piston(inside direct drum) its self could be leaking some what reverse would still be ok due to high line when put into reverse.

Just athought.

Rulebreaker · Jul 6, 2008

Bruce said:
You didnt loose the little pin that goes between modulator and the valve inside did ya??

Only thing applied in 3rd gear is forward clutches and direct clutches. Could possibly be the little check ball in the piston(inside direct drum) its self could be leaking some what reverse would still be ok due to high line when put into reverse.

Just athought.

The pin is still there. How do I check to see if that's the case? RB

Bruce · Jul 6, 2008

Rulebreaker said:
The pin is still there. How do I check to see if that's the case? RB

The only way to check that would be to pull tranny out and apart and air check the drums, by stacking the forward drum and direct drum on the pump stator and applying air to the appropriate feed hole in pump body.

Another option to testing the drums is to pull valve body and apply low pressure(no more than about 40 LBS to the feed holes in the case at the front of tranny.

C5 questions

Rulebreaker

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Sasquatch_Ryda

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projectnitemare

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gotmudd

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Rulebreaker

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Totalled

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Rulebreaker

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Rulebreaker

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Bruce

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