C4 REBUILD - BwoncoHowie Specs

[chuzie]

Houston, we have a problem!

Ok here is the deal...



Added fluid today to get up to required level. The leak that stopped yesterday from the shaft seal is back so I assume the only reason it stopped yesterday is because the fluid level got lower than the seal. NOT GOOD FOR ME!!!



Next... I installed the rear driveshaft and went through the range and I am getting nothing noticable in drive or reverse!



I need some direction on which way to take this and all suggestions are appreciated. I think I will have to pull the tranny out again because of the shaft seal but I want to try and nail down this other problem first to avoid coming down a third time. I guess I could pull the valvebody and have a pro look at it but I think a pressure test is in order first.



I still have no engine vacuum at the modulator but I do not think that would cause the problem I am experiencing, right? I do know the modulator controls pressure to some extent though.



I suppose I will have to run out and buy an oil pressure tester and hook up to the testing port to see what is going on but I wanted opinions first.



Thx,

Mike

 

[BwoncoHowie]

Ok here is the deal...



Added fluid today to get up to required level. The leak that stopped yesterday from the shaft seal is back so I assume the only reason it stopped yesterday is because the fluid level got lower than the seal. NOT GOOD FOR ME!!!



Next... I installed the rear driveshaft and went through the range and I am getting nothing noticable in drive or reverse!



I need some direction on which way to take this and all suggestions are appreciated. I think I will have to pull the tranny out again because of the shaft seal but I want to try and nail down this other problem first to avoid coming down a third time. I guess I could pull the valvebody and have a pro look at it but I think a pressure test is in order first.



I still have no engine vacuum at the modulator but I do not think that would cause the problem I am experiencing, right? I do know the modulator controls pressure to some extent though.



I suppose I will have to run out and buy an oil pressure tester and hook up to the testing port to see what is going on but I wanted opinions first.



Thx,

Mike

How many quarts did you add?

Which shaft is leaking?

If your air checks are good, you may only need to redo the valve body installation or look inside the valve body itself.

Hook up the modulator and complete the install, driveshafts, linkage etc.

 

[chuzie]

I added about 9 quarts which seems low but the dipstick was saying yes. Now that may have been temporary while the TC sucks it up but I stopped checking when the leak started.

The Front Oil Pump Seal.

I did partially disassemble the valve body but only to clean it, replace the gasket and the check balls. I did remove the manual valve and reinstall it and then started to remove the downshift valve. I got as far as removing the two retainers when I decided to leave well enough alone before I screw something up. Looks like it may have been too late.

Yep, all the air checks went very well so I just need guidance to troubleshoot the valvebody. I have no idea what valve serve which function so I really have nowhere to start the process. Is there any tech data/ documentation on the valve body I can reference with pics and instructions?

Anyway, I was trying to go through the range one more time before I pull the valve body and noticed something. I should have P-R-N-D-1-2 (6 positions) but I only get 5 clicks from the shifter linkage which means I am missing a click. Now it is disconnected from the column which means I am doing this by hand and I didn't screw up the rigging. Would this indicate I have the manual valve in back wards or something else?

Found a clog in the vacuum line for the modulator and got it hooked back up and still no change so I pulled the valve body.

Pulled the valve body. I didn't have the manual valve in back wards and the C-clip was in the correct position so we can eliminate that. I checked the shifting gear inside the tranny and it has full range of motion and I see nothing obstructing the manual valve unless I am blind. I did observe that the spring that connects to the lower valve body and provides detent spring pressure to the shifting gear has some new wear markings outboard of the roller bearing in the center. The marks are on the outboard fork. This indicates to me that the gear may have been riding on that part of the spring rather than the bearing but would that prevent the shifter from achieving full range? That is a tough one to swallow. I can try to tweak the spring's alignment and see what happens. If that does not work I need some guidance of where to go next with the valve body.

-----------------
I am done for the day, here is the update...

I got the shift spring realigned to ride on the shift gear correctly. Just needed a little tweak. I assume this was the problem with the "lost position" because now I have P-R-N-D-2-1. Must have been binding or something but it works now. I also hoooked up the linkage as suggested and got it rigged correctly.

Now since my fluid is on the low side, because of the front oil seal leak, things are slow in the system to respond but I did have reverse and drive. There was some hesitation for them to engage but again the fluid level is suspect right?

Tomorrow I intend to lower the tranny and fix this seal problem unless anyone has any further suggestions before I do so to ensure my issues are resolved. I would certainly hate to lower it another 2 times.

Thanks again.

 

[chuzie]

Nevermind. I got it going. Thanks anyway.

 

[sprdv1]

Good deal chuzie.....

 

[BwoncoHowie]

Thanks for the info!
Any word on your article?

The valve body article is now posted in the tech section, ...Sorry it took so long...

 

[BwoncoHowie]

http://www.gounitrax.com/

they were confused why I wanted that particular seal (CR 18676) for a C4 since it is a double sided seal. They said it crossed to a National 473179 which is a since sided seal. I couldn't give them an answer and just told them it was on my parts list.

The National cross-over equivalent will NOT work! It has to be CR 18676 or another brand that has 2 lips and 2 garter springs opposite each other. The National/Federal Mogul version was not designed for this and will get you into trouble.

 

[sprdv1]

The valve body article is now posted in the tech section, ...Sorry it took so long...

You're a good man..!

 

[BwoncoHowie]

You're a good man..!

Right back at ya sprdv

 

[BwoncoHowie]

This is the bare minimum I would replace on a 1972 & later C-4 rebuild for an EB.
Any additional pieces are pending a thorough inspection upon complete disassembly and cleaning of the components.

Transtar Part# Qty. needed Part description

26006C 1 REBUILD KIT WITH STEELS
26022BHD 1*** FRONT BAND (solid non flex type)
A26912 1 REAR SERVO PISTON
26036A 1 BUSHING, FRONT STATOR
26037 1 BUSHING, REAR STATOR
26010D 1 OIL FILTER SCREEN
36034B 1** PUMP BUSHING C-6
A26530 1 PUMP GEAR SET, C-4/C-5
26046A 1 DIRECT DRUM BUSHING
26052 2 BUSHINGS, SUN GEAR
26064 1 BUSHING, TRANSMISSION CASE
26074TA 1* METAL CLAD SEAL FOR THE ADAPTER HOUSING
(DOUBLE LIP)
26160G 1 MODULATOR, C4/C5 GREEN STRIPE
A26654K 1 SPRAG KIT, C-4/C-5 SPR & ROLLER KIT

*These adapter housing seals are often overlooked or neglected during a rebuild. If ignored can be the cause of a transmission or transfer case catastrophic failure.*

**I suggested using a C-6 pump bushing because it is much wider than the original C-4 bushing and will last a lot longer when installed properly.** This modification will also control the oil clearance better thus extending the life of the converter hub and front seal. This is one of the many Beef-up tricks I do when preparing a HD C-4.

***When changing from a Flex to a Solid Type band, you need to get the correct band strut or widen the slot in the original strut.

Selective items such as the pump and stator thrust washers, oversize steels, and clutchpack snap-rings would be ordered on an as needed basis depending on what is needed to set up the proper clearances during re-assembly.

The following are companies that have a reputation for selling OE quality aftermarket transmission parts and who I trust and recommend for my parts needs. They carry brands such as.
Borg Warner
Raybestos
TransTec
National
Federal Mogul
Clevite
Chicago Rawhide
As well as a limited supply of selected Genuine original equipment replacement parts.




http://www.transtarindustries.com/

This info was entered back in 2008, the atc website should NOT be used.

Here is another source I trust. http://natpronet.com/

 

[addicted]

Just curious. For a non do-it-yourselfer, how much would an HD C4 cost a guy. Im talking one with all your tricks and ready to bolt in? Thanks

 

[BwoncoHowie]

Just curious. For a non do-it-yourselfer, how much would an HD C4 cost a guy. Im talking one with all your tricks and ready to bolt in? Thanks

If you can buy wholesale, just under 200.00 including the rebuilt torque converter. I've never paid retail for tranny parts ever, so maybe someone else could chime-in. Today I log on from Beautiful Golden Colorado. Here for the weekend.

 

[73azbronco]

Well I did all those tricks retail, just under $300, then add a heavy duty Hughes towmaster torque converter $300, new: input shaft (mine was grooved- $220), rebuilt pump (again, cracked gear-$70), reverse drum (scored through-$40), bushing kit installed $70, adds up to $1000ish and about five 1 hr trips to Transtar and Hughes.

But I know it will work and work well. Buying a rebuilt would have been the same price, given me a 12 month warranty, but I know for a fact none of the "extra" parts I replaced would have been replaced.

 

[Viperwolf1]

Stock rebuilds can be done from $200-$300. All decked out with extra clutches and heavy duty parts it'll run somewhere in the neighborhood of double that. Not counting the converter, and doing the work yourself.

 

[addicted]

I think I have enough Bronco projects going right now without adding another one and Im not confident enough to tackle an auto trans rebuild on my own. Thats one item I would definitly want to buy, not build. I also dont get a warm fuzzy feeling from the local trans shops here. I was just wondering how much the complete HD C4 would cost. Ready to bolt in, fill with fluid, and go. And where could I order one from. Thanks.

 

[fungus]

Just picked up a C-4 in a '77 Bronco parts rig and contemplating building it for my crawler project. Any thoughts on the Art Carr reverse manual valve body?

New to auto trannies so can anyone explain the inherent "doubling" effect of the torque converter on gearing? For example, the gear ratio calculator I used yields:
C-4/ Klune-V 4.0:1/ 205/ 4.88 gearing, final CR of 94:1. 2815 rpm at 65mph w/ 40" tires.

435/ Klune-V 4.0:1/ 205/ 4.88 gearing, final CR of 256:1. 2664 rpm at 65mph w/ 40" tires.

Can anyone explain the difference in rpm at 65mph when both trannies are 1:1 final gear?

This rig will definately see a few rocks on the Rubicon and I want to get the best gearing I can. Anywhere around 175:1 + would be fantastic so I'm wondering where that 94:1 w/ the auto tranny really puts me. I love my NP-435 and have a 2nd one for the build but I've already gone that route w/ my '69. Willing to try something different and learn something new on this '68 crawler build.

Great info guys, appreciate it!

Fungus

 

[JackHoleRacer]

Hey guys! Having a problem w/ my fresh c-4 rebuild. After trans gets up to operating temp, wants to hunt for 2nd gear on up shift during easy acceleration. Shifts good and positive w/ more throttle. My trans guy &i checked for good vacuum(ok) & tried adj modulator & new modulator, No improvment. He said prob most likley the governor. We are having a hellofa time tryin to find a new one. Im so frustrated!! Tranny works so nice when cold, then shifts all stupid. Plus not being able to buy parts to fix it! Grrrrrr! Any help would be AWESOME ! I have a part # D722-7C063-C thanks

 

[BwoncoHowie]

...Just picked up a C-4 in a '77 Bronco parts rig and contemplating building it for my crawler project. Any thoughts on the Art Carr reverse manual valve body?

Fungus

Stay away from it. I think its a waste of money unless you are hard core into drag racing. Doesnt work well with stock column shifters anyway. B&M, Hurst, or Art carr, or similar click type shifters are needed to compliment this valve arangement.

 

[fungus]

Stay away from it. I think its a waste of money unless you are hard core into drag racing. Doesnt work well with stock column shifters anyway. B&M, Hurst, or Art carr, or similar click type shifters are needed to compliment this valve arangement.

Yeah, this rig is being built specifically for a Rubicon, hardcore trail type environment and I can see the utility in having 1st gear right next to Reverse. I would go with an Art Carr, B&M or the like shifter in a center console & wasn't planning on the stock column shifter. This is a frame up build and I now have two trannies sitting at my house to choose from, this C-4 and an NP-435.

 

[Action]

c4

I am also in the process of building a c4-It will be a full manual/rev valve body.It will also be a shorty hooked to a 203/d20 combo. I think the full manual/rev. will be the cats a@@. I am looking at this valve body www.broaderperformance.com I have heard good things about them. Just make sure you get a VB built with compression braking not a Drag VB!
Jack