Author Topic: C6 Problems--Advice Needed  (Read 2476 times)

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Stangman

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Re: C6 Problems--Advice Needed
« Reply #15 on: September 25, 2020, 02:31:00 PM »
I agree with Doug and that could be the noise you hear, maybe like a whinning noise. I dought the shaft splines stripped i would think that could take some HP to do.

Diogenes

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Re: C6 Problems--Advice Needed
« Reply #16 on: September 25, 2020, 04:07:01 PM »
At this point I'm not certain on how to proceed, though the points regarding the converter being the culprit do seem to take into account the vibrations I'm getting. I'd hate to drop cash on a converter if its a waste. Yeah, I like a manual trans better, my lack of automatic trans knowledge has me thinking its all witchcraft :)
1966 Galaxie 500 390 C6 Traction-Lock 9in.
1985 Toyota Celica Supra
71 Montego MX wagon 351C Toploader Detroit Locker Cyclone competition gauge/dash bucket seats/console
89 Texas DPS Police Mustang
71 Torino GT 351C 4V AT
68 Cougar 351W Toploader Traction-Lock 8in.
89 Dodge Omni modified 2.5 turbo from hell

RJP

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Re: C6 Problems--Advice Needed
« Reply #17 on: September 25, 2020, 06:46:11 PM »
A C6 is a relativity easy trans to rebuild. Just get a shop manual for help. If you have a 'no drive' in any gear I would first do a pressure test. There is a small plug near the band adjuster & nut on the driver side. For pressure confirmation test only you can use a 100lb engine oil pressure gauge, just don't rev the engine, it could ruin your gauge. At low idle there should be 60-65 lbs pressure. If there is no pressure the front pump would be the 1st thing I'd look at. It isn't common but sometimes the inner or outer pump gear breaks. I've had that happen on a C4, the outer gear broke into 5 or 6 pieces= instant 'no drive' in any gear.  Although personally I've never seen a C6 input shaft break or strip in mild street use I guess it is entirely possible. Be aware that there are 2 input shafts available. Early C6 up to about 1974 or 75 are 31/31 spline and will fit into the forward clutch hub either way, and later C6s use a 31/30 spline. I've seen a time or two where the 31/31 shaft is installed backwards [long spline into the converter] This pushes the converter forward loading the engine thrust bearing and I don't think I need to tell you what happens next. If you rebuild the trans I'd replace the converter just because, if for nothing else you will have a clean, debris free and confirmed good converter.  A rebuilt stock converter is only about $140-150.00 and not worth the effort to do the R&R twice.

Diogenes

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Re: C6 Problems--Advice Needed
« Reply #18 on: September 26, 2020, 03:12:33 AM »
Great information RJP--thank you, and thanks to all who've responded. Are there any special tools I'll need?

I've built multiple engines and toploaders, so I ought to be able to tackle this as well. I've always wanted to build an AT, so I  guess this is my opportunity.
« Last Edit: September 26, 2020, 04:31:04 PM by Diogenes »
1966 Galaxie 500 390 C6 Traction-Lock 9in.
1985 Toyota Celica Supra
71 Montego MX wagon 351C Toploader Detroit Locker Cyclone competition gauge/dash bucket seats/console
89 Texas DPS Police Mustang
71 Torino GT 351C 4V AT
68 Cougar 351W Toploader Traction-Lock 8in.
89 Dodge Omni modified 2.5 turbo from hell

GerryP

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Re: C6 Problems--Advice Needed
« Reply #19 on: September 26, 2020, 06:58:12 AM »
Great information RJP--thank you, and thanks to all who've responded. Are there any special tools I'll need?
...

You'll need a transmission spring compressor for the clutch pack.  Snap ring pliers.  Assembly Goo.  That's about it. 

KMcCullah

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Re: C6 Problems--Advice Needed
« Reply #20 on: September 26, 2020, 09:45:23 AM »
Eric has you pointed in the right direction. If your C6 isn't a high mileage unit, probably lost a sprag bearing in the torque converter. As mentioned, start with checking for oil pressure. The port next to the band adjuster or the front cooler line port will work for verifying pressure. Before pulling the C6, I'd drop the pan and check for heavy metal chunks. If it's a performance converter that you dropped some coin on, it can be fixed. If not, maybe this would be a good time to upgrade?

No smoke and mirrors with C6's. If you get into the clutches, there's a few different types of spring compressor that makes it easy.

This is one I have:


https://www.ebay.com/itm/For-Ford-C6-Rear-Clutch-Spring-Compressor-Tool-Repalce-SST-0152/392880280711?_trkparms=ispr%3D1&hash=item5b797d5487:g:6CQAAOSwEEVfDStL&amdata=enc%3AAQAFAAACcBaobrjLl8XobRIiIML1V4Imu%252Fn%252BzU5L90Z278x5ickkyMJZWL%252BqFSgQ3TOOe%252FNr7smA5Wsq9xlQujf7qZ6WEX42hkw8Ap4Cju95Bwv9KCHe%252BgRI2n3bKzRLTH56VCeI%252Fx99DJE5Kq6WlPv1iKI1Dv0PUPilJimsWQoZzWiaqseuo9aX0X7FpiwnF8ih0sZxrFwzBzjffLH5AYrnmDiBp8Zw1faAh7th9dNhOnoRtmDvFRget%252BBkOYfgPznBW6cbdV%252BZsFm4gimFJnrjma31WOYgfvAfrgwfTWt0JkVrVhhdIfTyLMU91dVG3TFFHNqH6DBOGoPmrgRZnggJLj4tpH1hoq1GbVMWb1D08wQEFu3l1oieX12m8wYlJsKzRjJTJoy%252FzaIyLi0rIFXKh5nkTdPIsK%252FphUIfxD%252B6rN%252BBcrbqLxXoxnA0kAxJlA9lrkiUi3Baforfm96fuy8%252BCQNkyvwljY6cU5YbLMtoRtRP5SW9G2WbvFMzReEKfXwN599bjcqiobNgwUYRAb9oC0wPy7IVjt5MMhwvj03i0pbDwkZlMulYf1z3w%252BRLoGanhDZvq9sEMbr%252BZQ6At9%252FTic%252FUWcOFXQnWgOi6pO%252BxVbupQxuEYbkUGauO6OcYmk3lNJETmQg4q1ZxctDN%252F5mwJuniCukYJmqdb%252FuEVt5h1iALHHS2QKa%252F6Pk5Xv9ebiSOsA8KfmPSH73LpZHaT%252BX10Gvl04nhWYo0ZMLVjkJCJPXzytgeVnXuhTuX5tKk9lpTR8YLuS77xizKzFi4BGE6yorFhAD3vKWqWVlswPFviVTugaklGHDt4bxzG0ODY8Jg6N4HyA%253D%253D%7Ccksum%3A392880280711f72c90944e504616973664ba47e0a0e1%7Campid%3APL_CLK%7Cclp%3A2334524

Kevin McCullah


RJP

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Re: C6 Problems--Advice Needed
« Reply #21 on: September 26, 2020, 11:06:14 AM »
 Generally an inoperative torque converter [stator] sprag will still allow the trans to operate but performance will be way off and sluggish. I've never seen a converter sprag failure cause a complete no drive condition. If the converter was a complete jumbled mess internally then perhaps yes.  Special tools: for Hi/rev clutch I use the forward clutch's Belville spring and 2 C clamps. For the low/rev I manipulate the inner sprag race using the 5 retaining bolts to compress the 24 low/rev springs in the piston. Strong word of advice: Install the low/rev piston's ball check valve at the 6 o'clock position. That is when the trans is in the up right operating position the check valve will be at the bottom. Easy to confuse since the trans case is usually up-side-down when doing the assembly. If the piston's check valve is not installed correctly a very harsh reverse engagement most likely will result. Don't ask me how I know. ::) Edit to correct spelling
« Last Edit: September 26, 2020, 11:13:01 AM by RJP »

frnkeore

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Re: C6 Problems--Advice Needed
« Reply #22 on: September 26, 2020, 01:46:24 PM »
The only thing, inside the torque convertor that would cause a compete, drive failure, would be a turbine hub failure. That is what the input shaft connects to, inside the converter. Input shaft could also be broken.

As RJP says, the stator will cause a loss of take off power, it only works when there is a differential in motion, between the output and the engine speeds. The oil spirals, inside the converter and is redirected, threw the stator and back against the pump side (outer converter housing), to increase the engine torque. When the turbine starts moving, it starts loosing it's torque multiplication. When the sprag clutch fails, it can't redirect the fluid, it just spins.

90% of the time, that a convertor fails, it will cause the trans fluid, to become contaminated with with metal, sticking spool valve and pressure relief valves. It makes a BIG mess of any close fitting parts.

Added:
Front pump failure would also cause a "no drive" condition. Both would cause a vibration.



 
« Last Edit: September 26, 2020, 01:50:51 PM by frnkeore »
Frank

Diogenes

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Re: C6 Problems--Advice Needed
« Reply #23 on: September 26, 2020, 04:19:07 PM »
More good info.

The odd thing I forgot to mention, when I put it in any gear it feels like it engages, but when I apply throttle nothing happens.
1966 Galaxie 500 390 C6 Traction-Lock 9in.
1985 Toyota Celica Supra
71 Montego MX wagon 351C Toploader Detroit Locker Cyclone competition gauge/dash bucket seats/console
89 Texas DPS Police Mustang
71 Torino GT 351C 4V AT
68 Cougar 351W Toploader Traction-Lock 8in.
89 Dodge Omni modified 2.5 turbo from hell

frnkeore

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Re: C6 Problems--Advice Needed
« Reply #24 on: September 26, 2020, 06:30:41 PM »
I'd say, that if it feels like something is happening, the front pump is probably ok as, nothing will happen, if there is no pressure.
Frank

67xr7cat

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Re: C6 Problems--Advice Needed
« Reply #25 on: September 26, 2020, 06:52:48 PM »
As I said need to check the line pressure. May be none or low. Think others have already explained how to do this. If line is low or none can be low fluid level, front pump, or a stuck pressure regulator. A C-6 has an aluminum valve body with metal spool valves. Get any dirt in there and they will sometimes stick.  If your line pressure is low to none I'd start by dropping the pan and valve body to check the pressure regulator.  This will also allow you to see if any metal or excess clutch material in the pan, as well see if the fluid is burnt.  If the pressure regulator is not stuck or have a broken spring then figure on taking the unit out and rebuilding it.

If you have pull it out your choice is to repair the failure or do a rebuild. A rebuild kit with new clutches, steels, seals, and gaskets are less than $150. As for the converter, I'd replace it. A good stock rebuilt one is about $100.  Unless you cut it open really cannot say what its condition is. Final thing is either flush or replace the oil cooler. Usually I just bypass the factory cooler and add an external.  Fastest way ruin your day is some debris get out of the old cooler and hang a valve in the valve boy or governor.

Diogenes

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Re: C6 Problems--Advice Needed
« Reply #26 on: September 26, 2020, 07:45:47 PM »
The fluid is not low nor is it burnt (at least on the dipstick). It has an aftermarket converter (JW Perf. Trans) and trans was professionally rebuilt by PO, engine is not stock but a mild build with an external cooler, finned cast aluminum pan with more capacity I presume. There was no indication of failure, though looking back I would have a loping idle when in gear at a stop sign/light that I didn't originally have (but not in park), which was happening for a couple months. I did replace the intake gasket earlier this year and tinkered with the timing, but it is within norms. The car got up and moved pretty well, but it may have taken a bit more pedal to get it, though it is impossible to quantify the feel. 

1966 Galaxie 500 390 C6 Traction-Lock 9in.
1985 Toyota Celica Supra
71 Montego MX wagon 351C Toploader Detroit Locker Cyclone competition gauge/dash bucket seats/console
89 Texas DPS Police Mustang
71 Torino GT 351C 4V AT
68 Cougar 351W Toploader Traction-Lock 8in.
89 Dodge Omni modified 2.5 turbo from hell

67xr7cat

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Re: C6 Problems--Advice Needed
« Reply #27 on: September 26, 2020, 09:15:44 PM »
Deep pan, did they use the extended pick up? Does the dipstick read right?  Are there any transmission leaks?  I know you added a quart, but I'd add another just to be sure, especially if there is a leak.

You said this started as a flare on the 2-3 shift and got worse from there. If something broke it would have broke and you would be dead in the water from the start.  I'd check the line pressure, if it is low or zero I'd pull the valvebody  and check that the pressure regulator is working right.  This will also let you see what is in the pan and go from there.

Is hard to tell if fluid is burnt looking at a dipstick.  Have had it look good, but be burnt when pull the pan.  If problem is not in the VB, you will likely find you broke a hard part, either the pump, input shaft, or converter. 

Whether you repair or rebuild will depend on if there is a bunch of debris in the unit. If there is you have to take everything apart at least to get all the debris out.  Hot transmission fluid is great for cleaning everything out and then it ends up in the VB and/or governor and then the fun starts....  the converter if it  is not the failure can get it flushed out, but again you cannot tell the condition of a converter without cutting it open.  The cooler you want to flush out. If you have a bunch of debris in the transmission if the cooler is on of those cheeses grater styles better off replacing it or putting a filter in the return line.

Now of course if you find the failure can just fix that and put it all back together. If you do not find any debris in the unit may be able to get away with that, but personally I'd rather do it once and be done, hence the above advice.

Good luck with it. 

cjshaker

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Re: C6 Problems--Advice Needed
« Reply #28 on: September 26, 2020, 10:15:11 PM »
I'd say, that if it feels like something is happening, the front pump is probably ok as, nothing will happen, if there is no pressure.

Not necessarily. A pump can be in partial failure mode. I've seen one that would shift into first but would not hold 2nd or 3rd. I've seen one that would feel like it would go into gear, but would not hold enough pressure to move, and I've seen one that would not move at all.
Doug Smith


'69 R-code Mach 1, '65 427 MR, 2x4, 4-spd, 4.30 Locker
2 1965 Galaxies with 390s
1970 F-350 390
1958 Ford Ranch Wagon 390

Diogenes

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Re: C6 Problems--Advice Needed
« Reply #29 on: September 27, 2020, 12:27:37 AM »
It has a stock dipstick, no leaks. Sat overnight and checked stick again tonight and it looked dark/material contaminant, but put stick back in and rechecked and was red--don't smell burnt either.

Flared when upshifting from 2 to 3, but went into gear. Flared once again while in 3rd, but then stayed. Drove it about 8-10 miles on state route without slowing, running up to about 60-65mph, had to slow twice to make turns but kept momentum and was able to get it in the drive, but I had to do some manual shifting to get it there. I put it into reverse to position for the garage and that was it, lost everything.

It'll be a few days before I can do further investigation, but I'll post my findings when I obtain them.

I really appreciate all the information all of you have provided.
« Last Edit: September 27, 2020, 12:29:42 AM by Diogenes »
1966 Galaxie 500 390 C6 Traction-Lock 9in.
1985 Toyota Celica Supra
71 Montego MX wagon 351C Toploader Detroit Locker Cyclone competition gauge/dash bucket seats/console
89 Texas DPS Police Mustang
71 Torino GT 351C 4V AT
68 Cougar 351W Toploader Traction-Lock 8in.
89 Dodge Omni modified 2.5 turbo from hell