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nattybumppo
04-05-2011, 08:24 AM
Well, my clutch is slipping in fourth gear going up a gentle hill at about 40 MPH. Guess I shouldn't have reused an old clutch! Anybody have strong opinions about which clutch to put in? The NAPA made by LUK in the US is cheap and close. Is there anything to the higher clamping power claim made by Centerforce and others? Who likes what they have?

74fj40
04-05-2011, 08:27 AM
I have an aisin from man-a-fre and it has held up pretty dang well. I have heard nothing but good things about those clutches. But at the same time I have heard nothing but good things about centerforce clutch except the pedal gets a little heavy at times.

Good luck!

Air Randy
04-05-2011, 08:43 AM
Sascha,

For the size of tires you have and the way you drive that rig, a napa clutch should hold up just fine for a long time.

rover67
04-05-2011, 08:45 AM
FWIW I am putting an LUK clutch in the 60 which has a v8. It had a centerforce clutch (which was made by LUK) in it before and It ran fine for about 70k mile of hard driving. Only a few times did i slip it so much it didn't grab and that was because it got so hot. I just am trying something different this time. I never liked the little weights on the centerforce clutch and when i removed it they were clearly running off center for most of it's life. They are also designed to grab tight at RPM's most of our motors never see.

i'd bet that anything you put in there would probably be OK.

RicardoJM
04-05-2011, 08:53 AM
The Bronco is running a clutch from NAPA, it has a lifetime warranty. The clutch is just fine, the slave cylinder is another story entirely. There are many who would indicate OEM clutch is the way to go, but all things being equal I would be ok with running a NAPA clutch - particularly if it has a lifetime warranty.:D

DaveInDenver
04-05-2011, 08:58 AM
They are also designed to grab tight at RPM's most of our motors never see.
This is the thing I don't get with Centerforce IMVHO, they don't offer use much of anything since they rely on clamping springs at low RPM just like regular clutches. Even with 22R mini trucks and dual cases I'm not sure they spin the engines up high enough, low enough to see the benefit. Yeah, Sasha, I would just get the OE style. I don't like skimping on the clutch and bearings because they're such a PITA to replace, so I would stick with known names, Aisin, NAPA/LUK, Koyo, etc.

TIMZTOY
04-05-2011, 12:21 PM
luk

nattybumppo
04-05-2011, 08:35 PM
NAPA/LUK it is then. Thanks for the input guys.

rover67
04-05-2011, 08:41 PM
Cool,

Don't forget to do the pilot bearing/bushing Throwout bearing, and get the flywheel machined if you haven't already...

L43dean
04-05-2011, 08:44 PM
Sascha, go Marlin! Fj-40 74' to 87'. HD 1200 lb. pressure plate. Made in Japan. Easy pedal to push. No problems with either of mine. This is a Cruiser specific clutch. $179.00. Dean.

nattybumppo
04-05-2011, 08:45 PM
The NAPA kit comes with those two bearings, but I just replaced the pilot bearing when I put the new engine in 500 miles ago. Unless I mangle it coming out, I shouldn't have to do it again, right?

nattybumppo
04-05-2011, 08:48 PM
Sascha, go Marlin! Fj-40 74' to 87'. HD 1200 lb. pressure plate. Made in Japan. Easy pedal to push. No problems with either of mine. This is a Cruiser specific clutch. $179.00. Dean.

There you go throwing a wrench in my plans, Dean. Does that include the throwout bearing, pressure plate and disk?

nattybumppo
04-05-2011, 09:09 PM
Dean, I just ordered the Marlin kit. Thanks for the tip

L43dean
04-05-2011, 09:18 PM
Yes!,[url]www.marlincrawler.com. Pressure plate, Seco clutch disc,Japanese"Nachi" release bearing,"Nachi" pilot bearing, alingnment tool. Everything I needed except clutch re-surface. Call Marlin, they recommended to me a slightly different "step grind" from stock. It has worked very well for more pinch, better purchase. And still a nice easy pedal, no cramps after a long day. Oh yeah, I have the awesome OTC pilot bearing puller, POP, it's out! You can borrow it. Lots more helpful info, check Marlins sight. Dean

rover67
04-05-2011, 11:04 PM
The NAPA kit comes with those two bearings, but I just replaced the pilot bearing when I put the new engine in 500 miles ago. Unless I mangle it coming out, I shouldn't have to do it again, right?

If you just did the pilot bearing i'd probably leave it in there.

Air Randy
04-06-2011, 09:12 AM
Just curious, did you pop your dust cover off and check to make sure your pressure plate bolts have'nt just loosened up? If those get a little loose they will let your clutch slip.

If they are loose, don't over tighten them as they are very easy to break. I think they get 12 ft lbs of torque but put Lock-Tite on them.

If you do it right you should be able to swap that clutch pretty fast since you arent doing a pilot bearing or rear main seal at the same time. Just pop the shifter cane out, remove the tc shifter, disconnect speedo cable & e brake, put a heavy timber (6x6?) through the windows of your hard doors. Hoist up on the tranny/TC with a good come-a-long to take the pressure off, remove the 4 bolts holding the tranny to the bell housing, disconnect the rear drive shaft at the diff, slide everything backwards. You may need another come along to pulll it backwards and hold it in place.

nattybumppo
04-08-2011, 01:33 AM
Thanks, Randy, I found two that were a little loose and snugged them up to spec. They were on opposite sides of the pressure plate. I also found a slight leak from the slave boot, as Ricardo suggested, not much though. I plan to replace the slave this week and drive it around a little to see if the slipping continues before I swap out the clutch.

RicardoJM
04-08-2011, 02:49 AM
I hope tightening the loose bolts is the easy fix for you.:D

nattybumppo
04-08-2011, 04:22 AM
I hope tightening the loose bolts is the easy fix for you.:D

My friend, it is way past your bedtime!

Air Randy
04-08-2011, 08:25 AM
A bad slave cylinder will have nothing to do with your clutch slipping. If the slave or the master is bad, you will have issues disengaging the clutch or shifting, just like you weren't pushing on the pedal.

Usually the only things that will make a clutch slip is if the disc lining is worn off, the pressure plate is getting weak, or some combination thereof.

powderpig
04-08-2011, 08:44 AM
Well you have not mentioned how the flywheel was machined? Was it a flat cut or stepped. As Dean mentioned, some of these fly wheels need a step and some do not. It may be possible that the fly wheel you have was not machined right. I do seen that you have a recent rebuild. Did you do the fly wheel at that time? If not you may want to measure the step if there is one and post it up. I think most steps are in the .020 range if I remember right.
Wonder what the different method that Marlin is suggesting to folks to do.
Later Robbie

L43dean
04-08-2011, 05:54 PM
Hello Robbie, On my 1980 and 1985 Hi-lux trucks the factory step grind is .020. Marlin recomends that both be step ground to .026. That is what I have done in each truck utilizing Marlins HD 1200 lb clutch. These two clutches went in the rigs in 2004 and 2007 with Marlins HD L52 and G54 trannies. It has all worked out very well. I have yet to determine what will be needed with the 68 Fj-40 with F145 and J-30. TLIF! Dean.

nattybumppo
04-09-2011, 03:55 AM
Robbie, the flywheel that we put in after the rebuild looked just about new. It still had distinct machine marks around the face. It was stepped, probably the stock 020.

The one we had taken out was clearly worn. Since then, I had that one machined with the standard 020 step. If I end up replacing the clutch I will use this one, but I'm hoping it was just those two loose bolts since time is running out before Moab.

Rzeppa
04-09-2011, 01:54 PM
I have 2 4-speed flywheels and a 3-speed flywheel if anyone needs to get one resurfaced prior to pulling their old one. It might save time by having the resurfaced one all ready to go so as not have to wait for the turnaround of getting their old one done after it is pulled.

nattybumppo
04-13-2011, 11:55 AM
It looks like Randy wins! I drove it up Floyd Hill yesterday with all the bolts tightened to their 14 lbs spec, and ... no slipping! Thanks, everybody for your suggestions.

Air Randy
04-13-2011, 03:31 PM
But hey, what do I know? After all I'm just a "Ford" mechanic :D. Glad to know we saved you the time and expense of replacing the clutch for now.