C4 shifting problem.... Help!!

[TwoHorses]

Can someone PLEASE tell me what the check valve and spring do that reside under the tab of the filter? My tranny guy rebuilt my tranny and I have the utmost confidence he did things the right way. But upon rebuild he noticed that these two parts were missing.

Well we decided to button it back up without them... and I took my tranny home. Put it all back together and when the truck is warmed up... the tranny will NOT go into reverse. And it slips like a SOB when going down the road and I try to get on it.

Something is wrong and I'm curious about the before mentioned parts. It would help greatly to know what that check valve and spring do.

thanks for your time!!

 

[NoJoe]

Hi: That's the throttle pressure limit valve and spring and you do need it, Joe.

 

[TwoHorses]

Do you think this could be the source of my problems?

Also... where can one purchase that check valve and spring?

thanks again...

 

[NoJoe]

Call some local tranny shops in your area and yes the slipping could be caused by not having the limit valve and spring but the shop that rebuilt it should know this, Joe.

 

[NoJoe]

I just reread my post and sorry If it sounded sarcastic I didn't mean it to be, also don't drive it that way until you replace the valve and spring, regards, Joe.:-X

 

[TwoHorses]

Hey Joe... no problem... I just pray this is the source of my problem and that it can easily be fixed. It's really depressing busting your ass all day to find out something isn't right.

I'd surely appreciate more feedback from anyone else that is knowledgable on this valve and spring. It would make me feel much better knowing this could be the fix I need.

again... thanks for your time.

 

[BwoncoHowie]

Filter & relief valve:
When changing the filter try to use a filter gasket It is better to include a filter gasket but not critical. When removing the filter be careful when loosening the last bolt. You will find a spring and a valve pushing the filter away from the valve body. Do not loose these vital pieces and make sure they get installed in their proper order.

The Hi gear Pressure relief Valve:
When installing the filter, the little valve goes into the channel first with the cup facing the valve body and the little peg resting inside the coils of the spring. Then install the filter and bolts positioning the retainer tab over the spring to hold it in place. Some C-4s have a ¼” steel ball instead of the valve in this location, these setups work fine but are not factory equipment on any C-4. The steel balls usually get installed when the technician looses the valve. ¼” steel balls seem to be more common than the valve and readily available in most transmission shops.

 

[TwoHorses]

I pulled the pan and filter... inserted the valve and spring properly... buttoned it all up and went for a drive. Initially backing out of the driveway I had reverse. Going down the road slowly starts out well. But as soon as I crack throttle to make the shift to second it's as if I pushed in a clutch. The engine winds up and the tranny stops pulling. When I slow down enough the tranny does shift back down into 1st gear from what felt like neutral where second gear should have been. I coast over to a section of road to do a Y turn and I go for reverse with no luck. No reverse unless I go up to around two grand and then it's like bangin the drivetrain as it's only partially catching.

I have no idea what's going on.

I checked the hose to make sure the vacuum for the modulater goes to a manifold port. I checked the hose by the modulator to see if there was fluid in it indicating a bad modulator (and yes.. the pin is in there)

I don't know what else to do. Hopefully the guy who put the tranny together will call me tonight and we can set up for him to come over. I have to believe it's something in the valve body area. I'm just praying I don't have to pull the tranny back out of the truck... how depressing would that be.

He used a brand new B&M rebuild kit... along with the minor shift kit option that came with the kit. My modulator is the "push in" type as well.. if that gives anyone any ideas or clues.

Any comments or suggestion are very much welcome.

thanks for your time.

 

[BwoncoHowie]

add more oil

 

[TwoHorses]

Yup... tried that when I got home. Watched it go up on the stick as I added a half quart at a time. I even put the dipstick on the outside just to be curious as to how far the stick went down the tube. I'd guess it goes to just about the bend in the tube where it goes into the pan. I basically over filled it further to see what the tranny would do. It pretty much acted the same way. It did however barely shift into second gear.. but not until I was around seven grand!!! And the reverse wouldn't work again. I barely got back to my house from around the neighborhood. It was slipping so bad that it was surely getting hot. And that was evident be the fluid that blew out the breather on the transfer case section connected to the tranny.

I don't know...

My tranny guy thinks it's somewhere in the valve body. So he's trying to track down another C4 and swap out whatever. I don't know jack about how these things work. I wish I had a manual.

My fastback had a C4.... and I swapped in a T5. I just don't think I'm up for another conversion.

add more oil

 

[NYLES]

"When installing the filter, the little valve goes into the channel first with the cup facing the valve body and the little peg resting inside the coils of the spring." BH

BH........I love you man! I sure forgot about that thing popping out as it fell on my chest....been worring if I had put it back correctly!