Installed new hays clutch (85-112 kit-11) , pressure plate and throw out bearing on ZZ454 with a lakewood bell housing. I can't maintain .030 clearance between cluh disc and flywheel without lo

The clutch is not releasing , several things can be the cause, check the following , Throw out bearing same size,clutch driven plate not fitted back to front, clutch fork is fitted to throw out bearing housing and pivot mounting, is the slave cylinder rod the same length, has the clutch free play been adjusted, has all air been bled from the master cylinder, If cable operated has free play been adjusted. Has the new pressure plate the same throw as the old one.

check that throw arm has not become disconnected from the pivot ball in side the bell housing during the installation of the gear box. This can some times happen and the arm is pressed against the opening and doesn't press on the pressure plate fingers.. Check that the fingers of the throw arm are still properly positioned behind the throw out bearing and not behind the bearing carrier.

some of these were manual clutch cable check adjustment of cable at firewall (bulkhead) and check for cracks around where cable goes through to inside cab common on old girls.
if hydraulic clutch system
check fluid in clutch master cylinder is it low?
it could have leaking slave cylinder on gear box bell housing or your clutch needs replacing, gear box out and replace clutch as a kit, pressure plate, clutch plate, thrust bearing (comes as kit) but dont forget to check and or replace the spigot bearing in the rear of the crank shaft when doing clutch kit.

Drop the drive shaft, tranny cross member, transmission and bell housing. Remove the clutch pressure plate and disc and get new set. Use a pilot/clutch alignment tool in the crank shaft pilot bearing/bushing to center the disc and put the new pressure plate on and torque it down. Then put the bell housing, transmission, cross member, and drive shaft back in, and your done.

you need to check the Throw out bearing, the Cherokee XJ has a Hydraulic Throw out bearing. the slave cylinder is Inside the bell housing and the transmission and everything needs to be removed to get to it. You will see two hydraulic lines that go from the slave calendar to the throw out bearing. chances are that the bearing is bad, maybe the roller part is ok, but the part that expands to push on the pressure plate is bad. I had this and it was my first hydraulic bearing, but it is a pain, because everything has to be removed to get to it. good luck.

bad pressure plate or stuck throw out bearing.

George,

Obviously you have a major problem with the clutch and related items. Have you checked for a good Pilot Bearing in the end of the Crankshaft? Have you used a Dial Indicator with a Magnetic Base stuck to the Flywheel and indicated the main Pilot Hole of the Bell Housing to determine if it is perfectly centered in relation to the Crankshaft? If it is not concentric within less than 0.005" then you have to get some offset dowel pins made to correct the concentricity problem.

I don't understand the Pressure Plate problem. You state that 2 bearings failed in the Pressure Plate? You mean the bearings on the Clutch Fingers? I just don't understand this unless they were damaged while installing the transmission. As to tearing out the center of the Clutch Disc this can also be caused by the lack of a proper Pilot Bearing and proper bell housing alignment concentric with the Crankshaft. It is imperative when installing the Transmission to place it in Gear and lock the Tailshaft so you can align the spline while sliding it into the Bell Housing and Clutch Disc. Once up to the Bell Housing take it out of gear so you can align the Bolt Holes. Tighten the Bolts to factory Torque specifications. Also, the proper Throw Out Bearing and Clutch Fork including whatever the fork pivots on. I have encountered many Bell Housings and/or Blocks where the Dowel Pins or Dowel Pin Holes in the Bell housing have been as much as 0.090" out of specification in relation to Crankshaft Centerline. I used to be an NHRA Stock & Super Stock Racer and have built hundreds of engines and aligned an equal quantity of Bell Housings for the manual shift vehicles.

Another thing that is very important is the Face of the Bell Housing where the Transmission mounts to it must also be indicated to less than 0.002" in relation to the Crankshaft so that everything is properly aligned. All Transmissions must have the proper Front Bearing Retainer with minimal clearance to the hole in the Bell Housing. This is a must as the objective is to have a perfectly straight line alignment from the true centerline of the crankshaft all the way through the transmission. Equally important is the Transmission Tailshaft bearing and Slip Yoke on the driveshaft. It all inter-relates to a perfectly straight line in perfect alignment with the Crankshaft Centerline.

Hopefully this information will help you understand just how critical the alignment of the Crankshaft, Bell Housing and Transmission is to proper assembly and Clutch life. All parts must have the correct sizes and minimal clearances and Alignment for long life and reliability.

Rapid Robert

You should be able to remove a cover or inspection plate at the bottom of the ****** bell housing to inspect and visually see the throw out bearing. It sound like it (the throw out bearing) completely went out or damaged the fingers it rests on to disengage the pressure plate. All clutches are pretty much the same. Flywheel bolts to the rear of the crankshaft with a pilot bearing in the center for the input shaft. The clutch disk is sandwiched between the flywheel and retained in place by the pressure plate. Followed by the throw out bearing which is operated by the release fork. You could have a bad slave cylinder, but that would not be the source for the squealing you hear. Sounds like it's time to replace the clutch assembly.

The first thing to do is to have the flywheel re-surfaced because a warped flywheel will cause the clutch to chatter or shudder when you let up the clutch pedal, and also be certain that the pilot bearing is replaced, it can be difficult to remove the pilot bearing from the end of the crankshaft and you will most likely need to obtain a good pilot bearing puller to remove it.

Clean the bell-housing and the rear of the engine block while the flywheel is being re-surfaced, and be sure that all of the old clutch material and dust has been cleaned from the bell-housing and the rear of the engine block, and contamination from an old clutch disk will lead to early clutch failure.

After the flywheel has been installed and torqued down, then you will need to mount the clutch disk and the pressure-plate assembly together onto the flywheel, and be sure that the clutch disk is facing the right way (usually the spring hub will go towards the pressure-plate assembly), and then start to install the pressure-plate assembly bolts but only hand tighten them for now. After the bolts have been started then use the clutch disk alignment tool that should have come with the clutch kit to align the clutch disk with the pilot bearing, and when you have it aligned so that the alignment tool easily slips through the clutch disk and into the pilot bearing, then tighten down the bolts to the pressure-plate assembly one turn at a time in a criss-cross pattern until the pressure-plate assembly is flush with the flywheel and then you can torque down the pressure-plate assembly bolts. This is a critical step and the better aligned that you get the disk and pilot bearing, and the easier it is to remove and replace the alignment tool, the easier it will be to install the transmission, and the transmission input shaft should slip smoothly through the clutch disk and into the pilot bearing and not have any difficulties mounting up to the engine, and if the transmission hangs up when you are installing it and and the transmission input shaft does not go straight in through the clutch disk and into the pilot bearing, it can damage the clutch hub and the clutch will chatter or shudder when you let the clutch pedal up, and it will shorten the life of the clutch.

After the clutch has been aligned then install the throw-out/release bearing onto the transmission input shaft collar and the throw-out/release bearing fork, and use a lithium based grease on the pivot points of the throw-out/release bearing fork and where the fork contacts the throw-out/release bearing, and if it did not come greased, then lightly grease the inside of the throw-out/release bearing with a lithium based grease and do not over do it on the grease, you want just enough grease to keep the throw-out bearing and the input shaft collar lubricated but still have a smooth operation to it, and you do not want to damage the clutch from oil or grease contamination as this will cause the new clutch disk to slip.

The transmission can now be installed into the vehicle and be careful not to hang the transmission input shaft on the clutch disk or the clutch disk will be damaged. I hope that this information will help you to replace that clutch with a proper quality repair that you will get the most out of.

possibly the throw out bearing....which is part of the clutch assembly