C6...

[LEB Ben]

Just for the sake of conversation...The C6 in the Bronco is getting on up there in age, and I've just assumed it's needed to be rebuilt. I'm completely transmission ignorant, but I've brought the bands in to spec, fluid looks good with minimal metallic...and the trans works well on the whole. Perfect running trans when it is cold, or the ambient temp is sub-70*. However, as the trans temp starts creeping when the ambient temp gets hotter, the 2-3 shift gets all kinds of sloppy. Will rev up somewhere around 4k and then slide in to gear. 3-2, 1-2, 2-1 shifts and reverse have never had an issue. When I re-did the engine, I took the original TC out and replaced it with the one bolted attached to the back of the replacement 400. It was flawless for a year or so. Anyway, the eventual plan is to rebuild anyway...just wanted to learn how to diagnose that symptom???


Side note, when it does get rebuilt I am planning on using E4OD/4r100 planetaries. Anyone have any good write-ups on that swap???

 

[SuperCab]

the sliping between gears thing sounds like a transmission on its last legs for sure...

not to be obvious, but I assume it is full of fluid? being low on fluid will do that...

 

[LEB Ben]

not to be obvious, but I assume it is full of fluid? being low on fluid will do that...

Me----><-----Matty bear

 

[fatherdoug]

Sooooo...., he'll take that as a yes?

My C6 was taking several seconds to move the truck after it was put in gear, but only on cold mornings(less than 32F). Since I know 0% about transmissions, I just had it rebuilt. The rebuild is about 7 years old, with no issues yet.

Sorry, Ben, I can't help you. I'm just trying to get my post count closer to yours.

 

[LEB Ben]

No worries...just posted for conversations sake. It'll get rebuilt regardless, I was just hoping to educate myself beyond just saying 'yup something's wrong, time for a rebuild'.

 

[Fellro]

It could be as simple as a shift valve hanging up. For the 3rd gear apply, you have the direct clutch and forward clutch applied. For reverse, you have the direct clutch and low clutch applied. Since reverse doesn't have the same delay, I lean towards the valve hanging, but it is possible the direct clutch pack is getting worn, as you would wait for the reverse clutch to apply before moving anyway. The main question to help determine would be if there was any of the black sediment in the pan. That is clutch material.

 

[LEB Ben]

^^^No black...pan looks pretty typical.

 

[Fellro]

I would think it is in the valve body then. The 2-3 shift valve may be hanging up, delaying the apply. In time, it will burn up the clutches though.

 

[LEB Ben]

Alright...had the vb out when I first noticed the problem to add a band aid shift kit...didn't know what I was looking at or for, but the 'problem' got better initially, then came back.

 

[Fellro]

 

[Fordzilla80]

^ Soooooo much simpler than my 5R55E.

 

[DNFXDLI]

That gearset was the route I went Ben, many places sell an aftermarket gear set as they are 1/2 the price of the Ford gearset. The guy that rebuilt mine did mention that something else had to be replaced as well...maybe a drum..I can check if you want.

 

[LEB Ben]

^^^Any info you have is always much appreciated.

 

[DNFXDLI]

I will try to give him a call in the next day or two. I just recall him mentioning that something needed either replacing or machining as Ford changed the way they did something in with the newer drums...damned if I can remember though.
I did go with the R-Code servo which is a fairly inexpensive upgrade and a Transgo shift kit.
That gear set is a cool mod though..a deeper 1st/2nd gear while still keeping 3rd the same for lower rpm.

 

[BuzzGun79]

Ben, from my experiences,you may want to replace the front Intermidiate Band over time and use the material on the band starts to crack thus causing an iratic shift,along with slippage as your describing.Your fluids should look a brownish color and have a burnt smell (like clutch material) this is a good indication that the band is worn.Alot of times people think the trans is going out,but the replacement of the band will fix the prolblem.they can be replaced by dropping the valve body,loosening the front band adjustment,you will have to cut one end of the band to remove it.the replacement band is designed with a free end and go's in fairly easy.I would give it a shot before pulling it out.I have saved many C-6's by band replacement.

 

[Fellro]

I could agree with that if the problem was shifting to 2nd, but it is shifting from 2nd that is the issue, the next clutch is not engaging fast enough, whether from slippage or slow pressure apply to the clutches. The band ONLY affects 2nd.

 

[BuzzGun79]

Thanks for the clarification Roger,I appologize.Grant it my experience is limited on automatic transmissions.I have only done a few builds way back in the day on my own vehicles.Most of the time in my service station days we sent them out to be overhauled due to time constraints and other vehicles in need of repair.Today i just dont want to get involved in building them,so i leave them to the ones who know how to do it right the first time....Well in my Trucks case the second...lol