auto transmission for 260z

[4zcar crazy]

I have a 260z early 1974.  ONly have one gear.  No reverse either.  Car sat for who knows how many years in southwest WA.

 

Fluid not clear and pieces in pan.  I want to rebuild.  It has a long tail shaft (over 1 foot long).  Not sure if original but rest of car is close.  

 

I will use service manual and the advice here.  Any idea were to get a rebuild kit that works and a flexplate and any other parts I will need?

[4zcar crazy]

Or maybe I should just change it to a manual transmission?  Is that more work than rebuilding the auto?  and is the auto from that time period worth rebuilding?

[datzenmike]

Look on line.

 

http://www.makcotransmissionparts.com/L3N71B.html  lists L3N71B but the clutches and plates should be the same.

 

http://atpautomotive.com/master-repair-kit-nm-1

 

 

 

Probably easier/cheaper to just throw a used one in. Any '74-'78 260/280x car, '74-'79 620 truck 3N71B is the same. 610 and 710, S10 (200sx), A10 (HL510) One year only '80 720 2wd will also work.  I have three sitting in my shed. All L series and all fit.

 

 

Or maybe I should just change it to a manual transmission?  Is that more work than rebuilding the auto?  and is the auto from that time period worth rebuilding?

 

You would need another complete z car for all the parts to do it correctly and quickly. Swap a used on from the list in is easiest.

 

Things to look for... Bright ruby red ATF that is clear and see through. Absolutely no discoloration or burnt smell. Change it anyway and instal new filter. Try to get the matching torque converter with it... yours is full of burnt ATF and they are near impossible to flush.

 

Things to do... install the largest auto trans in line cooler you can afford. Heat is what destroys all automatics and not much else unless you include over heating the automatic as abuse . Think McDees fryer oil. Once over heated the ATF is literally cooked and can't do it's job protecting the clutches.  Never tow with an automatic if at all possible. Don't downshift to slow the can when descending a steep hill. Replace the oil if you suspect over heating or the color changes. Automatics are good for over 100K if not abused.

[4zcar crazy]

Thanks.  I see your points. 

So, I think it would be much better to discuss purchasing a used one from you.  It does sound like it could be much more reasonable.

Besides, I was hoping to keep the car as stock as possible.  As you have noted, the transmission I now have is full of burnt ATF (and alot of particles.)  Towing and downshifting with and automatic must overheat the automatic and OVERHEAT the automatic transmission.  Now I get it even more.  It's just hard to know when a auto is overheating since there is no temp gauge.  I have recently added one to a GMC crew cab with a 4L80 because a mechanic (also) said it was the only way to monitor the tranny when towing loads.  He also installed a large cooler and fan for it.  The prior owner was told the transmission was shot.  So far it is working fine after the previously mentioned modifications and a VSS replacement. 

I am not exactly sure what the biggest cooler is because there are so many to choose from.  Do you go by BTU's?  Is there a better location for the cooler?  Does it help alot to have a fan?

[4zcar crazy]

How do you know a used automatic will be ok if it has been stored for years?  I heard that it must be kept full of fluid so that the seals do not dry out (probably overful).  That was another reason why I was thinking about rebuilding the one I have, but it also sounds like I would have to get a new torque converter since the old one is contaminated.  Not to mention some of the parts like the torque converter are very very expensive.   I like the idea of replacing it with a used one.

[4zcar crazy]

I was asking about he storage of the automatic transmission because I used a TH350 from a 1971 chevy that had sat for 20 to 25 years.  I did replace the fluid and filter first and it worked fine as far as I could tell.  However, soon after it started to leak fluid out of the shift lever and other places.  I did replace the front and rear seals (they have not leaked).  I loose a lot of fluid.  Oh well, I tried.  

[Alec 720]

I've had my issues with TH350's actually I've had too many tranny problems in my life.. Its a pain in the ass. I have two vehicles that are just sitting there the engines and everything works... except the transmissions. 

 

Good luck with figuring it out man!

[datzenmike]

On a Z car there's plenty of room to mount in front of the rad and let the fan do al the work. Hell I used the finned condenser from an old air conditioner on my old Omni. Worked just fine. A square foot of fins would be enough. Connect in line on the return to transmission hose.

 

I should be going to Canby this year, but never know until the last moment. I could bring one down but not interested in shipping.

[4zcar crazy]

I wondered about using old condensers for a tranny cooler.  Great job.  

 

I assume Vancouver Island is "the Vancouver Island" BC?   We have been talking about going to Vancouver for a long while, and I really like Vancouver Island.  Otherwise, are you ever a little south of Tacoma or Seattle?

 

Did you see me question about storing the automatic transmissions?  

[datzenmike]

Yeah about half way up island from Victoria. Never in the Ststes but for Canby. One trans was given me. The other two were driven in the last few years. Storage shouldn't hurt them. For the chevy one that sat for 20 years... maybe it was fucked to begin with and just never thrown away.