c6 transmission will not shift up to 3rd gear

I just pulled the line... the idle went way down. nearly wanted to die...

Was your friends cam fairly radical? mine is more of a modified stock grind...
I forget what ford called it. I want to say 303? I forget.. Im told its popular for its exhaust note... gives slightly better perormance but nothing radical. Idle quality is good.

 

I'd say that so far your dad's been lucky.


Far as the cam went, SBF, 305 cid, about 260-265 degrees advertised duration.

Sounds a touch lumpy at idle, but runs smooth now that it's in time.


Quit grasping at straws and get yourself a vacuum gauge.
Then you'll know pretty much what's going on.

And perhaps some of the trans-savvy people could ring in and comment if the C-6 operates similar to the C-4.

 

If 1-2 are short, then the modulator isn't the problem. A delayed high gear usually means have a kickdown or governor issue. Have a trans shop pressure check it, It will take them 10 minutes.

 

I'm not positive, but I don't think the kickdown comes into play here. Damn, if this were a C4 I'd be able to tell you for sure. As far as I know the C6 is much like the C4 in the fact that it needs vac*** to the modulator to shift all 3. Again, not 100% positive, but maybe C9 can diagnose as if it does and you could go from there?

 

Well, I did hook up the kick down rod yesterday... the bar runs down and come just in front of the ****ing linkage and the attachment at the end of the rod move up to attach to the linkage.

One guy told me it had to go behind the linkage... but it would not reach from there... and nearly perfect in front of.... when I put my foot down it down shifts hard. It will set you back in the seat. the guy also said thats why it wasnt upshifting... but Ive always been told on the c6 it is just the p*** gear. as well as the shifting is controlled by vacuum...

Im pretty much sold on the governor issue... there arent any leaks... the kick down works..we shall see tomorrow.. Im running it by the trans shop.

 

Did you fix the vac line yet. Always fix the things you know are wrong first. Like making the hard line, it needs to be done anyway. Its simple and cheap and may fix your problem. Not having the had line is half ***ed anyway.

 

Thats on my to do list tomorrow morning. I dont wanna be half ***ed. lol. I need to run new transmission cooler lines too.

 

Did I miss something ,or why arent you taking it to the guys that rebuilt it?? seems a lot of getting yourself in a knot over what an expert can diagnose and fix easily...and likely for free if its at the shop that built it and they are stand up types..

 

lol yes... well I wanted to rule out any of my uh ohs before I went pointing my finger at them.. then I would of felt like an even bigger dumb ****..

But this is a good thing to know for the future... should any of this come up.. I will have a better Idea of where to look. Plus someone else may be looking for something similar and this will help them out..

but after I run the hard line Im driving it in second gear for 5 miles to the trans shop to get them to look at it.... and since all things are a check with my work... they can cut right to the chase on there work. and not have to fix mine.

Thanks for the help will keep posted

 

oook.. well I have an issue!!

my valve body is incorrect...
The trans is an early style --1967
the Case is a late style--80s

Apparently the two arent getting along?
He asked me to pull a late model by late 1980ish
c6 valve body.

Another issue is my flywheel is the wrong weight... the truck vibrates...

 

Boy, you in a heap of trouble...

I'm no expert, but I'd say that might be your problem.

 

yeah, basically need to go find a late model c6... drop the pan and pull the valve body... or buy one off line somewhere... I might try calling tci or some where that sells modified valve bodies... dunno.. we shall see.

 

You can't put this on the trans shop? Or did they just R&R exactly what was in the trans when you gave it to them?

 

Yes he rebuilt the trans with all the hard parts coming from the older trans...all the hard parts were in great shape... and 1 to 2 works great!

Im eye ballilng this part

http://store.summitracing.com/partd...880856+4294904004+4294925024+115&autoview=sku

however... if this will fit from 67 to the 90s... why wouldnt the 67 work in the 80s case?? doesnt all add up...

He checked all the governors. and air checked the trans... everything checks out.. but it just wont up shift. ahhh well. we will figure it out..

The guy at the shop was going to pull one from a trans he had.. but his was a early model trans as well.. and he didnt have any late model c6 ******s laying around... so.. if this tci part wont do the trick ill have to go to a salvage yard and pull one... but I would more than likely have to buy the whole thing and spend a 100 bucks or so anyway. for junk I dont need! tho im sure the guy would be willing to buy the rest of it. im out a hundred bucks or so either way. ****s. but gotta do what you gotta do. I rekin.

 

I wonder... could the intermediate roller clutch be in backward? (as in flipped upside down on the low-reverse clutch hub) From what I'm looking at here that should only be holding in 1st-Drive. The roller clutch is released in all other forward gear ranges and reverse. To achieve 3rd-drive the forward clutch and reverse/high clutch are applied. Source= ATSG service manual for C6

 

Next time you should try to rebuild it your self. I did my c-6 its really pretty easy if you lay it out the way you take it apart, and have a manual. With a shift kit all that's different is you have to drill a hole in the plate under the valve body and take out a few springs. I realise that you don't need to rebuild this one, you should try to post in the wanted section for a valve body. I used to have one after moving it from place to place I finally s****ed it. I would have given it to you if I still had it.

 

From what I have been told and read all the C6 valve bodies will work in the all of the cases. The pre 1967 VB's have the shift detent built into the valve body and the post 1967 use the detent in the case. Both can be interchanged as long as you commit to one detent style or the other. I have a late model VB if you need one. PM if you are interested. I am picking my botched C6 up from the ****** shop tomorrow. I was having similar issues but my problem ended up being metal on metal issues causing metal debris that clogged the govenor and the VB. $430 later I will be back on the road. I am not happy that me doing the rebuild went south and cost me the extra cash, but atleast I know it will be right now.

My C6 is going in my 1965 Ford F100 but it is behind a gas guzzling 352 FE.

 

This thread is getting beat to death. First, I take it that reverse works, so that eliminates rev-hi clutch. Next it drives in forward gears 1 and 2, so forward clutch is ok. If the 1-2 shift is at speeds it suppose to be, then governor is probably ok. Kickdown rod is only for forced downshifts, nothing else.

Vacuum modulator is the throttle valve. Yes it will control shifts, but at various vacuum stages. It probably is ok too as the 1-2 is ok.

So cutting to the chase, IMHO your problem is case or valve body related. If there is a port for the rev-hi clutch apply to monitor pressure, I would check that first to see if the rev-hi clutch applies at 25 Mph and little throttle or whatever the manual says is the normal speed for 2-3 light throttle shift.

There is another way of checking this. Remove valve body and use compressed air to check clutch applies. If they apply then in all probability your valve body has issues, such as stuck valve or check valve ball. May also be plugged at the circuit which applies the rev-hi clutch at 2-3 shift.

A remote possibility is that the intermediate clutch is not releasing at 2-3, but I doubt that is happening as 1st works ok.

 

Just called TCI about their auto/manual street fighter... he can use any core to build what I need... should I go for the 76 and up ? or the 66 and up? my ****** guy said i needed to find one 78 and up. to be safe.

 

About your C-6 prob.If you think theres a prob with the kickdown rod,disconnect it then drive it all your doing is eliminating kickdown it will still upshift .If the lever at the trans springs back when you push it it's connected inside ok.To adj the kickdown go to the carb and (with it hooked back up)pull the excelerator to wide open throttle and you should have 1/4 inch clearance between adj bolt and the lever of the carb.The C-6 has a low-rev clutch and a rev-high clutch.I would put a modulator with a green stripe on and also adjustable.There is a set of modulator pins that are different lengths to get you in the ball park(I've crumbled up a welding rod to make pins before)Basicaly the longer the rod the later and harder the shift,each full turn in on the vac. mod.is 3-5 lbs of pressure.Question? when you manually upshift it do you take it up to say 25 then pop it into 2nd then take it up to 30-35 then put it into 3rd?Will it go back into first gear by itself?Or do you have to stand on the brake and steady give it more and more gas til it pops into low? =stuck primary valve in gov.If a vac line gets spongy the mod diaphram is ruptured (meaning vac side is ****ing trans fluid to the engine 9trans fluid and rubber don't get along.I'd try adjusting the band again (loosin 13/16 nut,hold and run adj stud in to 10 ft.lbs.then back off 1and 1/2 turns,hold and lock jam nut down.Poss.rev.high clutch,vac.mod.(need 15-19 in. vac)broken seal ring to high clutch on pump,Tell me what happens when you try some tests and I'm sure one of us can help you.

 

hey, ive run the truck with and with out the kickdown ... ive adjusted it... still get no third... Im not sure about which mod valve ive got it was painted black with the rest of the trans... but the transmission guy said it was ok. I was told that if the mod valve worked for 1 and 2nd it should work for 3rd....

it wont manually shift into 3rd either... Ive tried many times. as far as first and second go.. they operate like normal. down and up... no revving necessary.. works just fine. The trans guy did air check everything.. the governors were all good... and according to him the thing should shift up to third... it just wont... he called a guy that knows more about c6's than him... and informed him that that since the guts were out of an older and the case is a newer... that I had the wrong valve body for something to operate correctly.... that I need a late model valve body... so Ive called Transmission parts supply and I can get a rebuild for 115 or a TCI for 160.

on another note.. the transmission at first after being rebuilt.. never actually driven at the time... would not go into park...but after driving it ... it will go into park.. its a little picky still. it kinda has to roll into park.

 

just an opinion from a guy who rebuilds transmissions for a living. You are chasing your tail with vac*** and kickdown adjustments. It sounds like you have either governor problems or a stuck 2-3 shift valve. I would also say that your "transmission guy" is a little shady.

 

nah... they are really good.. he has just never done a early model to late model case swap... he checked all that out you talked about... and it all works as it should...
he used a term.. air check.. apparently there is a difference in the valve bodies from mine which is an early model year.. and the one I need which is a late model... he showed me some things and how they work and he said that mine operates correctly. I did talk to another guy out of little rock that I know...and he confirmed that I would need to get a new valve... so im in the process of doing that.. but will likely wait till after the new year and Christmas to buy.

 

So if you drive it and come to a stop your sure it's going back to first,right? It may be a valve body thing but before you spend any more dough on it lets talk about it a little more.The guts are basicly all the same,infact when ford came out with the 4 speed (e4od)it still has a lot of the same stuff.In order to air check the trans you have to remove the pan and valve body to blow into the oil p***ages in the case.The problem here is the Direct or rev./high clutch(one and the same)If he air checked it he should hear a dull thud .If he did all this and it did have a thud,now we can ***ume that the direct seal rings are ok on the pump,and the piston seals are ok also.***uming the band is adj.The linkage has to be adj.also.Is this floor or column shifter?

 

Genie 23 inch floor shifter.... I have wondered about the linkage... Ive even sorta pulled it forward and backward to see if it would pull into 3rd.. however.. when pullling it down into gear.. it pops into drive just before the notch and rest on that notch there... so I know that it is initiating in the right spot... now pulling it down into the second makes not change... down all the way initiates first gear. back up 2nd works.. up to the notch..where third should be... nothing occurs.but remains in second.. easing up higher it fades into neutral.easing it back down it initiates 2nd again.. and easing it down just goes back through the same routine. however the park action is still sorta odd.. it sometimes pops into park.. like it doesn want to go but then it goes... not always but sometimes... if I pull up to a stop and while it is still rolling a bit. and pull it into park it goes in fine.

 

With the car running pull the shifter back (I don't know about that shifter) slowly til you just feel the ****** go into drive.Don't touch the shifter leave it alone and go under the car and disconnect the trans linkage or if it's nut on an elongated slot.Think about what you've done ,you found drive at the trans now you have to move the shifter to the sweet spot and have someone keep a little pressure on it to keep it against the detent(in the car)now go below and lock her down.If it was a linkage prob.you should now be good to go.Forget about park for now we just want to see if a misadjusted linkage is the prob.cause if the linkage is off a little, the manual valve in the trans will be off allowing pressure to bleed off where its not suppose to.

 

Will do. Hopefully I can do this tomorrow if not it will be next wed... im going off on a work trip. Ill inform ya how that turned out. Thanks for the input.

 

I know I made it sound confusing but I don't know your shifter but what your doing is putting it in drive at the trans and now your aligning the shifter to matchI'll watch for your post

 

If the trans shop used all the guts out of the early trans including the reverse piston in the case then the early valve body should work also. The main difference is the reverse check ball. In the early trans it is in the reverse piston in the case. In the late trans it is in the valvebody. You have to have a least one check ball. More is okay, none is not. If your valvebody has the detent in the valvebody then you can remove the detent spring from the case on your later case. Hope this helps a little.

 

I've been watching this thread very closely. I was hoping by now it wouldve been solved, I have a 1994 Ford F450 wrecker 2wd, with a 7.3L non turbo with a C6 behind it, I just bought it, previous owner stated trans was rebuilt, ( i have a reciept for it) says bench build, It does the same thing. shifts from 1st to 2nd quickly and never into third. The 1st to 2nd shift is really quick. The truck came with a 4speed auto, column shift via cable with push ****om overdrive. Now has the C6 with a B&M floor shifter. The valve with the vac***e at the back of the trans appears to be brand new.