Gearbox ID

[Werup]

Hi

I have already search so many places, and cant really figure out which gearbox the PO installed in my car. Im asking in here because I have to order alot of parts from the US and im currently stock in Norway and my car is in Denmark. But have to order the parts so the car can get road legal this summer My gearbox needs some bushing and some seals, but im not a 100 % sure on what i have.

Here what i think:

- 5 speed close ratio from 1981 280z because: one mounting ear - Speedo bolt a 6 o'clock

What confuses me:

Short ears for shifter - close to straight gearshifter - bushing installation at shifter

I have som pictures of gearbox but only installed, hope you guys can help me. Cause I will return in June, way to late to order parts :stupid:

Best Regards

Martin

[Zed Head]

The gear shift levers will swap across all 71B transmissions. Even though MSA, for example, sells short shift kits for different year cars.

And the ears-on-the-shift-mechanism things is wrong I believe. I have a 76 4 speed, and and a 78 and 83 5 speed in the garage and an 80 in the car. The length of the ears doesn't tell anything.

If you want to get closer to knowing what you have, measure the ratio of 5th gear by marking the driveshaft and turning the engine until the driveshaft turns one revolution. Then see how far the crankshaft rotated. The exhaust hanger and the speedo bolt put you in the 80-83 range. I think that the main difference in parts is the 5th gear synchro ring though. If you're not buying a 5th gear synchro ring, parts for the 80-83 5 speed should work.

Eurodat knows more and might have some comment.

1980 - .773

1981-83 - .745

[Werup]

Super i was a little unsure on how the items fitted across, Ill try to ask Eurodat then. See if he has anything to add, if not im going to order the seals ect.

Thanks for your quick reply.

Best Regards

Martin

[grannyknot]

Have a look at this,Differential Ratios

[Werup]

Thanks Grannyknot i have seen those, but i am not near the car the next month, i simply forgot to check when i was there last :/

[EuroDat]

Hi Martin,

I got your PM, but thought I would post here.

Of all the 5 photo's, the first one intrigues me the most. The speedo bolt is positioned at the bottom, but the housing doesn't seem to have the same shape like the later 280ZX transmissions have (See centre photo). It could be a 280ZX 1980 version. I have never seen one of the 1980 versions. Maybe someone here has a photo of a 1980 transmission with this section?

The PO probably used the shifter out of the 240Z. They are, like Zed Head said, interchangable although some do have a slightly different shape.

Another senario although unlikly: The transmission is from the 720 truck series which had this transmission fitted behind the L20B, Z20, Z22 and Z24 engines. It will fit, but he must have used his 240Z bell housing to do it. He would also use his shifter because the trucks had a longer version. This would mean its a wide ratio transmission. there are 3 versions and the later version being the same as the 280Z wide ratio, but Im no expert on the 720 transmissions.

This will give you an idea of the ratios used in the 71B.

You have to order parts to get it road legal?? What do you want to do to the transmission? If its a rebuild (bearings and seals) then even a bearing and synchro kit for a FS5W71C will work with exception of the front cluster shaft bearing. You don't need to know if its a wide or close ratio for those parts.

Shifter bushings, gaskets, seals and shaft nuts are all available through your local Nissan dealer and the bearings can be purchased at a bearing supplier.

Ordering a bearing kit from the US can cost a lot more due to shipping.

If you need part numbers, let me know. I have most of the original and replacement numbers.

Chas

[Werup]

Hi Chas.

Thanks for your reply. first I'll answer you on why i had to know now. I have to order alot of parts together from US to get it shipped with a freinds who is going to import a car from US. So im using the space in the container for my items, need a new frontwindshield. And i was not sure that the parts i needed where interchangeble But if the nissan dealer have those i get them through him, ill PM you with some questions on part numbers instead.

So i guess the next thing is to try and turn the gearbox when i get back and ill post i answer to what gear ratio the gearbox have. Did not have to know on what ratio, just hoped that somebody could give me a year of it By the way, it seems like the gearbox has some numbers and har on unit, so i dont think the PO changed the bellhousing. But ill double check when i get back.

/Martin

Edited May 1, 2014 by Werup

[Zed Head]

Wow, that's a good catch on the missing bump. I managed to get a picture of my oily 1980 transmission, by sticking a camera under there and taking a bunch of shots. It has the bump. So does my 83, but the 78 stops sharply at the mid-point parting line. You know though, if you look closely, you can see the bump on Werup's picture. It has a slope to it which doesn't really show in Eurodat's picture, which looks almost perpendicular, maybe due to camera angle. The slope is easily visible on my 83 sitting in the garage, and visible in my oily picture.

One other thing I notice, which doesn't seem to get mentioned, is that the early transmissions have a double dust shield at the drive shaft yoke. The one on the drive shaft slips in between the aluminum housing and a separate shield on the transmission, with the transmission shield ending up on the outside. On the later transmissions, the driveshaft shield ends up on the outside, they got rid of the shield on the transmission.

Edit - went a little crazy and retook some pictures, showing the dust shield and the shifter ears. You can see the short ears on the 4 speed, but long on 78 and 83 5 speeds. I almost went overboard and cleaned the garage for better pictures, but managed to stop myself.

Edited May 1, 2014 by Zed Head

[EuroDat]

Nice photo's Thanks Zed. That answers my question on the 1980 box. I have also heard the 1979-80 "close ratio" transmission uses a fibre 5th gear synchro, but like I said, never seen one or had one apart.

Martin.

Here are the parts I used in my transmission 2 years ago. The prices are Nissan dealer prices in Holland. I ended up buying a overhaul kit. The parts not in the kit came from the Nissan dealer.

Chas

[grannyknot]

I had two close ratio trannys apart this winter for rebuilds, one early and one late,

The only real difference between the two that I could find besides the 2nd and 5th gear ratios was that the early tranny has a cast 1st gear shifter gate (on the left) and later was cast and machined

onto the 1st gear shift rod. There is also some small changes with square locking keys replacing ball bearing locking keys.

Edited May 2, 2014 by grannyknot

[EuroDat]

Hi Chris,

That is interesting. Your photo's clearly show brass teeth on the rings on the fifth gear synchros. Like I mentioned, I have read about fibre synchros on the fifth somewhere, but never seen one or known anyone who has. It could be just a myth or in other Nissan models.

How did you go with your transmission rebuild?

Thanks for posting

Chas

[Werup]

Thanks Eurodat, thats a big help thanks alot for reply. And Zed, thanks for those pictures aswell, ive got my order down now Zed nothing like some good encouragement to do a clean out

I will definitely go for an overhaul on the box in the end.

/Martin