how hard is it to kill a 280zx 5 speed?

[Rheis]

dont know if this is on here somewhere but with the search function down ......

I have a later 280zx 5 speed (the one with one ear.. not two) in my car ... it has always whined from day one but very suttle. When I first got my car it was only half full with oil and when I noticed it I topped it up with redline oil. Andy from Specialty said last year sometime it was eventualy going to die or something like that... basicly saying I have to do something about it .. I have posted about this before and it was recomended to have it rebuilt but after spending a fortune on the rear end I cant afford that (for now anyways) ... anyhow the whine is slowly getting worse and I am noticing more different noise when the rpms go high like 4000+ and I let off .. I haven't and don't engine brake with it.. So my question is how much longer could it last? I am planning on going to Penticton with it this friday it should be ok right? and is it possible to rebuild it myself? maybe change the bearings? This transmission has the more desireable gears so if I could do a GOOD rebuild myself that would be great.. any help is greatly appreciated

thanks Rheis

[okayfine]

So my question is how much longer could it last? I am planning on going to Penticton with it this friday it should be ok right? and is it possible to rebuild it myself? maybe change the bearings? This transmission has the more desireable gears so if I could do a GOOD rebuild myself that would be great..

There is zero way to tell how long your transmission will last. In my experience, I got tired of the noises a bad transmission makes long before it ever failed. Your's could fail tomorrow, it could fail two years from now. It could just get more noisy and never fail.

WRT rebuilding, do you have the knowledge and special tools necessary to disassemble/reassemble a transmission? For an example of the process (but not directly applicable to your transmission) you can look at:

DQ Volume 7 Issue 1 - Tech How-To: Dog-Leg 5-Speed Rebuild

which goes through the process of rebuilding a dog-leg transmission. You could also look in a FSM (for a 280ZX, obviously) for the procedure. IMO, it's not for the faint of heart. If you were going to open up the transmission at all, you should inspect all the parts and replace what's necessary, not just bearings.

And with that said, it would sure seem easier to buy up a known-good ZX 5-speed and just swap it. There are always people upgrading their L-series drivetrains to KAs or SRs.

[Derek]

Mine's been making a terrible racket for forever now mostly in off throttle 4th gear situations, but I don't worry about it. I'd just say make sure you have CAA gold!

[datzenmike]

So you want some assurances and a guarantee you can make it to Penticton and back then... With a pair of snap ring pliers (or two screw drivers) and a 12mm wrench you can remove the front case half from the adapter plate and get at the front counter bearing. This is likely the source of the growl. Power is transmitted through the counter shaft in every gear, (including reverse) except 4th. Under load, acceleration/deceleration, the main input and counter shaft are trying to be forced apart. When the bearing is worn, besides making it's own noise, the counter shaft is pushed sideways and mis-aligns the drive and driven gears causing more growl. If you notice that it's a little quieter when in 4th gear then this would indicate a worn counter gear. Why would 4th be quieter? Because 4th gear isn't really a gear shift but a connecting of the main input shaft directly through the transmission and out the tailstock. There is no need for gears as one input turn equals one output turn. The countershaft, though driven, isn't transferring any power and will often be much quieter.

To get at it all you need is a pair of snap ring pliers and a 12mm wrench. This will get you this far:

[img]http://i138.photobucket.com/albums ... .jpg[/img]
In the picture above, behind the lower counter bearing is the counter drive gear, turned by the input shaft drive gear just above it. Next to it just to the right is 3rd then 2nd and 1st at the far right side against the adapter plate. There is no 4th 'gear'.



The upper bearing is the main input drive bearing. Note the groove for the snap ring to sit in. The smaller 56mm bearing below it is the counter bearing which is easily drawn off with a gear puller and a new one hammered on using a block of wood. A good bearing should turn smoothly without roughness or play in any direction. Be sure to check the input bearing too. Although more work to replace, now's the time.

To keep your new bearing from wearing out any sooner than it has to or to keep an older tranny running quiet longer, avoid towing , climbing steep hills or passing while in 5th gear. This will reduce the side loading on the counter bearing from heavy throttle at higher speeds. 5th gear should be used for light or part throttle highway cruise speed and should be downshifted into 4th for passing.

[Rheis]

ok so it made it there and back I was gentle with it, passing in 4th (it is quieter in 4th) only used 5th at cruise (130km ish my speedo is off ..at max of 4000rpm) Unfortunately on the way back I had lots of extra cargo and the car didn't like it especially the trans. Anyways once in a blue moon I would hear a thud or like a knock when I would shift gears (seems ever since I got my 4.11 lsd in the beggining of this summer) this was happening more often I guess due to the weight on the way home ... also when lifting off the throttle I heard splashing and like a crackling and sizzling of oil or something like it.. I don't think I could take the trans apart and rebuild it properly. However I think I could change all the bearings although I assume there is something else wrong? So from here should I
A: change the bearings (I do have a toasted early zx 5 speed I could dissasemble for practice)
B: put a wtd add on here and hope for the best of luck
C: wait till I get some disposeable $ which might be a bit and have it rebuilt by....?
D: wait and use the broken trans front case and try to make that hybrid 240sx trans (but then the driveshaft and motor mounds have to be altered correct?

thank you for your help so far it is much appreciated

[okayfine]

Anyways once in a blue moon I would hear a thud or like a knock when I would shift gears (seems ever since I got my 4.11 lsd in the beggining of this summer) this was happening more often I guess due to the weight on the way home

This is likely a complete separate issue.

A: change the bearings (I do have a toasted early zx 5 speed I could dissasemble for practice)
B: put a wtd add on here and hope for the best of luck
C: wait till I get some disposeable $ which might be a bit and have it rebuilt by....?
D: wait and use the broken trans front case and try to make that hybrid 240sx trans (but then the driveshaft and motor mounds have to be altered correct?

Just get another ZX transmission and install it.

But based on the little diagnosis you've done, it might not solve anything, really.

[heirfaus]

Anyways once in a blue moon I would hear a thud or like a knock when I would shift gears (seems ever since I got my 4.11 lsd in the beggining of this summer) this was happening more often I guess due to the weight on the way home

This is likely a complete separate issue.

Maybe rear suspension is not all tightly bolted in? Maybe ring and pinion are not set up correctly?

[okayfine]

Maybe ring and pinion are not set up correctly?

This. Or bad u-joints somewhere in the mix.

[hang_510]

once in a blue moon I would hear a thud or like a knock when I would shift gears (seems ever since I got my 4.11 lsd in the beggining of this summer)

my rear end makes this same noise seriously! R160 3.90 LSD
more of a 'clunk' when shifting, sounds like a u joint but they are all new...
i havent openned it yet

[Rheis]

thanks for all the input. Now I have to look for a good trans any leads?

Anyways once in a blue moon I would hear a thud or like a knock when I would shift gears (seems ever since I got my 4.11 lsd in the beggining of this summer) this was happening more often I guess due to the weight on the way home

This is likely a complete separate issue.

Maybe rear suspension is not all tightly bolted in? Maybe ring and pinion are not set up correctly?

Its probably a U joint as Andy built my r180.. I installed all of it then they cambered it and did a nut and bolt check so I will check the u joints as everything else is brand new