TO bearing on a 5-speed in a 260...

[Guest thewingnut]

Hey, folks...(new here, know a few members, namely DaveyZ and aux)

 

 

I've got an early 260 with the stock motor, and a 5-speed behind it. The throwout bearing is going out, and I need to replace it soon. This is my daily driver...

 

I'm told there are two different TO bearings that are possible with this combo,either one from a 240-260 with the stock 4-speed or one from a 280, for the 5-speed.

 

Any ideas? I can try crawling underneath and looking for parts stampings if that'll help, although it's probably more what's inside that is critical.

 

It's going to be a one-shot deal, so I'll need to buy several bearings and return the ones that don't work.

 

Thanks in advance!

[evildky]

it would appear there are 3 different throw out bearing collars but they all use the same bearing, the bearing is pressed onto the collar but with a brass punch and sitting it inside a piece of pip of between the jaws of a vice it's not too hard to get off

[auxilary]

Just to check, would that be a throwout bearing or a pilot bearing? It's the bearing that sits on the clutch fork itself and presses against the clutch. Those are different sizes, afaik, between 4 and 5 speed transmissions.

 

I'll be helping thewingnut with this on saturday, I'm pretty sure I know what the issue is, but just wanted to check to make sure he gets the right parts

[evildky]

throwout bearing is the one that presses against the tines of the pressure p[late to actuate the clutch, don't know about the 5 speeds but the bearing on the 4 speeds seems to be universal, but there are 3 different collars that the T/O bearing is seated on

 

the pilot bearing sits inside the crankshaft the small part on the tranny input shaft goes into it to keep the trans alighned with the motor, and those are all universal as well (at least with 4 speeds and the ka 5 speed)

[auxilary]

just as I thought, thanks!

[technicalninja]

Throw out bearings are available with or without the collars. Cheapest without the collars. The bearing itself is the same part for 71-89 240Z through 300ZX. They also fit most other Nissan applications between those years. Nissan was very good at using 1 part for all applications in quiet a few instances (not just clutch stuff). This across the board parts coverage is more common in the earlier years and by 90 parts were becoming very specific for each different model.

The collars are different and they match the clutch pressure plate not the engine or the transmission. If you put a 83 5 spd in a 72 and use the 72 clutch better use the 72 collar or it will not work. On the other hand if you put a 280Z pp in a 72 with a 72 4 spd use the 280z collar.

Most of the pressure plates 240-300ZX will bolt to any of the flywheels. Only big difference is Coupe set up is smaller diameter that 2+2 or Turbo.

Differences exist when using some of the turbo parts (ie I think the T5 set up uses a different bearing and collar than everything else but I may be wrong) and the very early 240Z 3 peice trannys (removable bell housings).

I will not purchase or install a bearing which states "made in China" on the packaging. I have had failures with the cheap Chinese parts. I prefer "made in Japan" followed by Germany then America. The price difference between these different manufactors is minor compared to removing the tranny again.

Buy a good quality part with out the collar and it should fit fine.

I remove the old bearing from the collar by supporting the bearing on the back side using a open vise (two block of wood same height will work fine) being careful to not touch the collar with the vise then take a socket which fits just inside the recess in the collar (1/2 in dr 21 or 22 mm doesn't matter which size as long as it fits snugly in recess) and lightly tap the collar out of the bearing with a SMALL hammer (I use a plastic tap hammer). This should not take very much force at all. You do not want to nick inside of collar as this surface glides on the collar support mounted on trans. If you damage it clean it up with fine file and sandpaper. Usually I sand the roughness off of the tranny collar support as gouging is usually evident. After cleaning the collar I install it by holding new bearing in one hand, placing collar in it, and tapping it in with SMALL hammer. This should also take little force. I DO NOT back up new bearing on anything but my hand as it is easy to ding the bearing races if to much force is used. You could have the new bearing pressed onto collar but I worry about the person doing the pressing- They don't have to pull the tranny back out if something goes wrong. Tapping it back together in my hands has always worked fine and it costs nothing. Also I can "feel" when the bearing is fully installed when using my hands which a press cannot. DO NOT hammer directly on the new bearing. I then pack grease into the INNER recesses of the collar. I use Sta-Lube Boat wheel bearing grease (the blue stuff) as it is waterproof, is more slippery that Owlstuff, and has a half life of eons. It does not turn into a thick waxy mess like the original Nissan grease. I also use it at collar to throw out arm contact points and throw out arm pivot point. Wipe off any excess after putting bearing/collar assembly back on tranny snout as you don't want this super grease on your PP or disc.

 

Changing the pilot bearing is a good idea when replacing any clutch part. This part is also an across the board part. Any 240z-280ZX part number will work fine. You have to remove clutch then remove it with a bearing removal tool. Many parts stores will lend or rent this tool. There are ways to get this out with out the tool but save your self the hassle and obtain the tool- it will save time and sanity. The new bearing has a lubrication process that many do not know. It is a sintered brass bushing (same stuff as those brass air blocks for aquariums but with a finer grain). Many will say it does not require lubrication but it does. Place new bearing on thumb with one of the open sides up. Fill bearing with engine oil until it forms a meniscus at top (almost overfilled forms a curved surface) carefully cover with other thumb and apply pressure slowly. You will see the sides of the bearing "sweat" oil when the oil is pushed though sides of bearing. I once cracked a pilot by applying pressure to fast. go slowly. Drain excess oil out of bearing and blow bearing out with air. The oil will be in the bearing matrix and the pilot will last much longer. Once again you don't want a bunch of excess loose oil as it can contaminate your clutch. I use a wooden dowel to drive new bearing into end of crank but a deep 3/8 socket which fits snuggley into crank hole can be used- just be carefull not to nick end of bearing as the material it is made out of is very soft. Drive it most of the way in with wood (2X4 block) and finish with socket.

Aux- try the pilot trick even if you don't install it. Everyone I show it to is suprised.

One bit of mis-information needs to be cleared up. The pilot bearing supports the input shaft at the engine side of things. A large solid pin at top and a dowel at the lower left bell housing bolt aligns the engine and trans. If either of these are missing catastrophic tranny failure WILL occur. Often I replace the lower dowel as it can be miss-shaped or loose in block which can allow it to move into bell housing mount hole recess defeating its purpose. it should be tight in block and fit snuggley in bell housing. I have never had to replace the large pin at top of bell housing.

 

Sorry for the long post, It sounded like you had never done a Z clutch before and I didn't notice Aux was going to help until most of the typing was done.

Good luck!

Rick

[Guest thewingnut]

I bought a bearing from Napa Auto Parts without a collar, seems you can't get them with the collar anyway. I'll just have to be careful in removing the old one. The one I bought is marked 'Nachi Japan' so it should be a well-made part.

 

I should include a few more details:

 

It's very difficult to shift into first while sitting still. Less so with other gears, but still difficult. This is with the engine running. It's a piece of cake to run through the pattern with it off.

 

With the trans in gear and the clutch pedal in, the car will creep on a level surface. Less when it's hot, more when it's cold. It's also easier to shift when the car has warmed up. Double clutch and it shifts relatively well, shift normally and it's notchy. Gear clash is a 50/50 proposition.

 

I've had other suggestions; flush the gear oil, bleed the clutch fluid (level is topped off right now), slave is bad (have a new one). Of course, these will be tried before yanking the trans.

 

Any other suggestions? Thanks for the help!

[technicalninja]

I should have asked more questions before my first post. The problem symptoms have changed my answer. The throwout bearing is not your problem. TOBs going bad exhibit noise and roughness during clutch application; some times the noise is so loud that you would think you had a cat entangled in your clutch. You might also feel vibrations in your clutch pedal (sort of like warped brake rotors but at a much faster rate).

Your problem is something else. Here are my thoughts.

What is happening is power is being applied to the input shaft when clutch is applied.

First of all- Does your clutch pedal feel normal or does it have excess free play? The pedal would feel floppy at the top of its travel and not seem to do anything until it was applied quite a ways- possible problems are bad master/slave, improper selection of TOB collar (using short collar where long collar is needed). Air bubble in clutch hydralics, improper slection of clutch master accuation rod.

Has your Z ever shifted properly?

Are you a new owner of this car?.

Has the clutch just been changed?

What is recent history of work done which may affect clutch opperation?

I noticed another thread which posted about modifing the 240Z clutch pedal stop (in pass comp) to facilitate the longer travel 280Z clutch throw. Your early 260 is best thought of as a late 240 and has the same body as a 73, late 260s had the 280Z body. It may benefit from this mod.

In 20+ years of wrenching I have come across 2 PP that lost their ability to disengage. This is very rare but would cause the problem you descride.

The clutch hydralics are easy to check and should be proven good before you pull tranny.

As long as clutch hydralics are good and the car has shifted good at sometime in its recent past your problem is most likely a bad pilot bushing. It is binding slightly on the input shaft and applying a small amount of engine torque directly to the input shaft bypassing the clutch entirely. If this is the problem it is damaging the tranny NOW.

Changing gear oil may be necessary as your tranny has been grinding syncro rings and gear syncro lugs but it will probably not help your symptoms.

If pilot has been binding it will have damaged front tip of input shaft. Clean off embedded bushing material from input shaft with a fine file and sand paper. minor gouges in shaft are not a problem but any raised areas are. Test fit the new pilot to shaft before install. It will show you your problem areas.

I have never seen a pilot bushing ever fail on its own. It has always been caused by something else. Not being lubed as in my above post, nicked on installation, or tranny/engine misalignment.

If I didn't know how old clutch was I would just replace it as an entire set if I was going to pull tranny anyways. Clutch stuff is not very expensive and I am lazy-only want to do job once. For stock replacement I prefer Diaken (SP?). LUK and Valeo make pretty good stuff also.

The Nachi bearing you purchased is what I would look for as a top choice. They were the original supplier for Nissan anyways.

Please post what you find when you get it figured out.

 

Rick

[auxilary]

well, I'll chime in. Finished everything in about 2 hours. When wingnut brought the car in, the clutch pedal had almost no pressure, I thought the problem was elsewhere. Flushed tranny fluid (stupid filler plug was bolted solid, couldn't move it, so I filled it through the reverse signal switch). yanked out master and slave cyliders, replaced them (used MC and slave from my 240z), replaced line, new gear oil in the differential. Put cleaned out the clutch lines, adjusted the MC rod, put it all back in, bled the line, wingnut took it around the block a couple of times, it runs like a champ!

 

I had a wrong diagnosis of hte problem based on the description, but it's all good now.