280Z 5spd Transmission Clutch Fork

[datzenmike]

well, this thread has been dug up once already, lets do it agin.

 

i'm having very similar issues. l20b in my 521. trans was a 4spd (unk what out of. worked fine other than being loose and tired. swapped in a short 5spd and took with it, the TO bearing, collar, and fork. used the same 225mm flywheel. and installed a new exedy clutch/pressure plate.

 

installed all of the above the fork wont engage the clutch enough. cant adjust the rod on the slave anymore as the fork is maxxed out and touching the transmission window. seems to me I've got the wrong collar? or poss the wrong fork? I thought this was a simple swap as all my readings said just keep the TO bearing collar and fork with the flywheel and clutch setup. it worked on the 4 spd. but not on the five. thoughts?

 

You have two different parts here. The exedy clutch and the release collar from some unknown clutch 5 speed. Put your old 4 speed release collar in and if the exedy was a perfect match to the current flywheel and all should be ok.

 

If this is a dogleg 5 speed, it was on a car with a 200mm clutch so the release collar is matched to it. YOU have a 225mm clutch so the 200mm collar is going to be too short for it and no wonder why you have run our of travel.

 

 

While it is out, replace the release bearing. ALWAYS replace this high wear item. There's nothing like pulling a transmission 3 months later because had 90K miles on it and failed. $15 is cheap now isn't it.

 

The L series release bearings are all the same and used on every '70s vehicle made and at least, as far back as the mid 60s and even on the much later 300zx and into the late 90s VG33 Pathfinder. Almost no way to get the wrong one.

[spdcrazy]

yes. the collar seems to be the issue. The exedy clutch kit came with a TO bearing, and it was larger in diameter than what was in the 4spd. I verified that the 4spd bearing matched what was supposed to be in the 4spd 521. I then replaced it with a new one, I, too, have put in an old TO bearing and regretted it deeply.

 

but what I don't get is the collar I installed came from the 4spd, and the 5spd is not a dogleg. so it should work, but it definitely seems to be to short, the pivot ball is intact and in good shape with the washer behind it.

 

I still agree that my collar is the problem, but what collar do I need? I have seen 4? different height collars.. .

[datzenmike]

 

You have two different parts here. The exedy clutch and the release collar from some unknown clutch 5 speed. Put your old 4 speed release collar in and if the exedy was a perfect match to the current flywheel and all should be ok.

 

If this is a dogleg 5 speed, it was on a car with a 200mm clutch so the release collar is matched to it. YOU have a 225mm clutch so the 200mm collar is going to be too short for it and no wonder why you have run our of travel.

 

 

While it is out, replace the release bearing. ALWAYS replace this high wear item. There's nothing like pulling a transmission 3 months later because had 90K miles on it and failed. $15 is cheap now isn't it.

 

The L series release bearings are all the same and used on every '70s vehicle made and at least, as far back as the mid 60s and even on the much later 300zx and into the late 90s VG33 Pathfinder. Almost no way to get the wrong one.

 

Again, if the replacement clutch is an exact match to the old one, your old 4 speed collar will work.

[spdcrazy]

DatzenMike. I understand what you are saying but I don't understand how I potentially don't have the exact right clutch? Three sizes of flywheel. Measured mine at 225mm. Ordered an excedy clutch for a l20b 620 with a 225mm flywheel. Am I missing something here?

[banzai510(hainz)]

you need a 620 t/o bearing collar  as your using a a 225mm clutch.

 

 

L20s can use a 200mm flywheel(from a car) which you can use the stock T.O collar and use the stock clutch also(roadster also)

200mm from a SX is also slightly different. but I think you can get away with the difference if one uses the 521/510 fork arm has a hole as its adjustable rod for the slave

 

 225mm is a truck flywheel and you ordered a 620 kit so the diaphrarm height is different so you need the 620 Collar.  I think I seen Collors for a 620 on PartsGeek.com.

 

 

Now we are not mind readers on what parts you have NOW and or swapped

 

 

I thinkk your mistake was using the parts from the new trans as its set up for that clutch on the other motor.   everything is based on the clutch diaphrame height and the dia of the flywheel.

[Stoffregen Motorsports]

There were about three different clutch cover depths or thicknesses, however you want to call it. With the clutch bolted onto the flywheel, measure from the tip of the fingers to the flat face of the flyuwheel. Now do the same for the other clutch. Are the measurements the same?

[spdcrazy]

Thought I was pretty clear that I swapped my parts from the 4spd over. However I get what you are saying. I know how to measure the height of the pressure plate now. Then I'll know what collar to get. Thank you all for the knowledge.

[datzenmike]

33-35mm finger to flywheel surface for the 225mm

 

No matter what the finger measurement is, higher or lower, the slave will run out of travel* if a collar isn't selected to keep the clutch arm in the same position. I believe¹ the distance from the very back of the collar, closest the transmission, to the flywheel, should be 89.4mm or 3.52". Now very likely a few mm isn't going to matter as long as it's close. Also I wrote this down a long time ago and have no idea where I got it. If you have your transmission out, and hold your collar and bearing against the diaphragm fingers, and carefully measure down to the flywheel clutch surface, ALL installed 200/225/240mm clutches should measure the same.

 

¹I haven't confirmed this 89mm measurement, in fact it may be to the two surfaces on the side that the clutch arm contacts. If someone has a properly working clutch and collar and have the transmission off, measure it and we'll see....

 

* How critical is this?

 

 

Top is my 710 4 speed and below a zx 5 speed arm. Pretty sure they are interchangeable. Now take a look where the pivot ball fits into the arm. Fulcrum point if you will. Its that larger round depression in the arm. Now if it was in the middle 1 inch on slave travel would equal 1 inch of release collar movement. Roughly it's 2 to 1. So a collar that is only 1/4" too short requires the slave to travel an extra 1/2". The clutch slave is only designed to travel 1.18" so nearly half it's travel is used up doing nothing.

[Stoffregen Motorsports]

 

i'm having very similar issues. l20b in my 521. trans was a 4spd (unk what out of. worked fine other than being loose and tired. swapped in a short 5spd and took with it, the TO bearing, collar, and fork. used the same 225mm flywheel. and installed a new exedy clutch/pressure plate.

 

 

Thought I was pretty clear that I swapped my parts from the 4spd over.

 

 

No matter what the finger measurement is, higher or lower, the slave will run out of travel*  see....

 

 

 

This is getting confusing.

 

spdcrzy - you say you swapped all your parts over, but you did install a new clutch. The problem has to be with the clutch. It could be the ball pivot. I don't know if you've checked that yet.

 

Mike - if the new clutch he installed is different, then that's the only measurement that matters.

 

Also, someone here said it, that all the T/O bearings are the same. I don't think that's true. There is a small bearing with a raised contact surface towards the middle (smaller OD), then there's a larger bearing with the surface relatively flat and the contact surface towards the outside (larger OD). If I recall, the bearing styles coincide with the finger shape. Some fingers are flat and some are curved.

 

Back to you spdcrzy, unless you find another problem, always look at the parts you replaced first.

[spdcrazy]

A lot of very valid points here. The engine/trans is in the truck still. Sadly I'll be pulling them tomorrow I think so I can get a good look at what's going on.

 

My pivot ball is in good shape.

 

I do believe there is two TO bearing styles, maybe one superceded the other? Idk. But one was bigger in diameter, it came with my clutch kit for a 620. The other style was smaller and was on both of the other trans.

[datzenmike]

The clutch arm can only travel and have effective geometry, through a certain range. As the height of the pressure plate 'fingers' varies so does the collar that holds the release bearing. A 'taller' clutch needs a shorter collar, a shorter clutch needs a longer collar.

 

The original 4 speed collar should work IF the replacement pressure plate is identical. I think I said that somewhere...

 

Again, if the replacement clutch is an exact match to the old one, your old 4 speed collar will work.