Archived clutch install gone bad! NV4500 SBC con ofe

[FreeBMW]

I just wraped up my clutch install. i got it all back together... . started it up..... and the clutch wont disengage. I replaced the flywheel/disc/pressure plate.





with the truck in gear and the clutch to the floor if i start it it rolls.



the clutch pedal feels soft.



I have removed the slave cyl 2 times now to dbl check it and it looks right.



PLEASE HELP I cant imagine taking that beast out again!

 

[MDW]

The only thing I can think of is what my nephew did and thats was he didn't put the slave rod back in. Do you feel any restriction when you set on the clutch pedal??

 

[Shovelhead]

I've seen a few posts where folks didn't apply the lube to the splines on the output shaft during reassembly, and the clutch disc was binding instead of sliding.

 

[FreeBMW]

Guide rod is in there..... and we did lube the shaft/pilot bearing/throwout bearing fork .



I was just playing with the slave cyl and i think the problem lies there.





is there any way to bleed the clutch? i dont see a bleeder screw anywhere!?!?



With the slave cyl out of the trans bell housing the rod wants to go forward... . with it fully extended the clutch pedal is impossable to depress. Is that right?

 

[Shovelhead]

Are you abolutely sure the disc isn't installed backwards?



Just throwing out ideas here,

 

[FreeBMW]

Originally posted by Shovelhead

Are you abolutely sure the disc isn't installed backwards?



Just throwing out ideas here,

I am pretty sure it will only go together one way..... if you try to put the disc in with the spring hub side in the wrong direction the pressure plate wont mount correctly (bolts wont be long enough)

 

[Shovelhead]

The only other thing that comes to mind is a bad pilot bushing/bearing in the flywheel that is siezed on the input shaft, acting like a solid coupling.

 

[R.E. Miller]

Hmmm, this happened to me on my pick-up when I upgraded to the nv4500, it turned out to need a new hydrualic system. Same deal, fire it up, clutch never disengaged. replaced entire system, works like a charm. Could not figure out how though, I measured rod travel, and it seemed that there could have only been about 1/32" difference between what the old system could push and the new one, but it worked.



Good luck,

Russell

 

[bighammer]

Does it really feel like it's locked together or released most of he way? Mine needed some adjustment when I got it together. Truck wouldn't really roll, but if it were started in neutral, I couldn't get it into gear.



(adjustment was to the pedal with grinder and welder )



BTW, welcome! always glad to seem more MI members. Oo.

 

[robertyoke]

I had the same problem after pulled trans. out of truck . Turned out to be bad master cylinder. I called dealer to get part (after all other parts suppliers said they did not have listing) they only sell the complete unit full of fluid ready to go... . for some major $$$$.

I kept looking found the individual parts at standard transmission in Texas . . cheap. So cheap I replaced slave clyinder also for peace of mind down the road.

 

[FreeBMW]

I needed to move the truck to get my motorcycle out (since i couldnt drive the truck). I had to take it around the block (messed up roads) so i started it up in gear and limped around the block. i did notice that if i pushed the clutch in and gave it "go" pedal that the clutch would slip a bit but not fully disengage. so i am thinking it is the master or slave cyl. But what that i did during the removal/replacment did i do to cause this?

 

[csevers]

Try pumping the pedal a lot and or remove the slave very slowly and reinstall very slowly you may have a lot of air in the slave cylinder after my clutch job the first day and a half was very misserable then the pedal came back to where it should have been and seamed to release about 1/2 travel, at first it released right off the floor like 1/2 inch off the floor. You probably didn't do anything wrong just bad luck.



Craig

 

[dieselburner]

I had this problem. You need to get the air out of the hydraulic system on the clutch. After I changed out my clutch, l I drove out to a railroad crossings where there was a good grade and pumped the pedal. I drove up at different angles and pumped the pedal several times at each spot and when I was done the clutch worked fine.

 

[FreeBMW]

Update.........

I spoke to SBC this morning & based on my description they think its the clutch hydraulics. My truck has 93k miles and SBC has seen high mileage truck with weak slave/master cyls have this problem. I ordered a new setup from the dealer ($220) IT includes slave/master and resovure all pre filled. It should be here tomorrow morning and I will post to let you guys know if its fixed (X fingers crossed X)



Thanks for all your help.

 

[FreeBMW]

2nd udate

I got the new clutch hydralics today & installed them... ... Same problem!!!:{





So I called South Bend back & they asked if there was any way to get the truck to them..... I said I'll get back to them and attempted to go for a drive..... the NV4500 shifts very well without the use of the clutch . So I called them back and Woody gave me the name of their local prefferred shop and I set it up for tommorrow morning. Its a 3 hr drive for me but its all highway so I will be in 5th gear and forget it most of the time.



I am REALLY impressed with the customer service at South Bend and would recomend them to anyone based on this alone!



I will post tomorrow when i get home with the results... .



If i were a betting man (i am ) I am going to guess that i fugged up the pilot bearing while reinstalling the trans and its not allowing the input shaft to spin freely.

 

[FreeBMW]

Fixed! yay!

Well I am real glad I took it down to Soutn Bend to have the experts look at it. It turned out that the input shaft was bent! how it happend I dont know... . but it was suggested that towing too heavy of a load or making too much power could. $200 for a new input shaft and I am back on the road.





Big thanks to Fred's clutch and Woody at South Bend clutch for working hard to get me back on the road.

 

[wawazat]

Just saw this Clayton

Glad you got it fixed. Could your dyno pulls have caused this



Todd

 

[Deezul1]

Dyno runs are less stressful on drive line than street driving(racing). My 1st time on the dyno had me worried as my clutch was slipping in 4th and 5th when the boost was up but guys with experience told me not to worry and there was no clutch slippage on the dyno and that was a 400HP pull too. Prolly not dyno related.

 

[csevers]

Good Deal

$200 sound pretty cheap for an input shaft I think you got a good deal. No more hole shots huh?!



Craig