Jump to content
jcd0402

71 510 4 speed transmission mount

Recommended Posts

Well just to get this struggle out of my head, is the 620 mount and the 510 mount the same? According to eBay, the 510 and 620 are interchangeable, but since rockauto doesn't have a 510 part I don't know how to get a part number for it.  

 

Another quick thing is that the transmission will also be mounted on an L20B with an L16 clutch as opposed to the stock L16 with an L16 clutch. 

 

Thank you! 

Share this post


Link to post

If the clutch cover on the L20b is 200mm then use your L16 clutch arm/throw out bearing collar, if it is larger, use the arm/clutch collar that was on the transmission you got the L20b from, the clutch collar follows the clutch cover, not the transmission.

 

Also it depends on what year transmission mount you are talking about, early stuff is different than late stuff on the Datsun 620 truck.

  • Like 1

Share this post


Link to post

The '73 620 uses a same transmission and may match the 510 but '74 and on used a different transmission. Maybe....

 

To be able to use the L16 (200mm) clutch you will need an L20B 200mm (bolt pattern) flywheel from a car. Truck flywheels only fit the larger 225mm clutches) Further, if you're thinking of using a 5 bolt L16 flywheel on an L20B... it won't fit. If you have a 200mm 6 bolt mount L20B flywheel see wayno's post above.

  • Like 1

Share this post


Link to post

Share this post


Link to post

All L series 4 and 6 cylinder flywheels look outwardly the same. They can be broken down into 5 bolt to crank, for L16/18, and 6 bolt to crank for L20B/Z20/22/24, KA and all L series 6 cylinders.

 

It's the bolt pattern on the face and the contact surface diameter that determines what diameter clutch and pressure plate will bolt up to it. You should easily be able to measure across the wear or contact surface to identify them.

 

200mm is 7.87"..... L16/18 and L20B cars

225mm is 8.85"..... L20B trucks (includes the one year only '74 truck with L18) and KA and Z22 cars

240mm is 9.44"..... Z24 and KA trucks but will fit any 6 bolt crank.

Share this post


Link to post

 

I believe that is a late 620 mount(disc brake trucks?), that is used on the 720s also, I believe early 620s with the short 4 speeds used different transmission mounts, but I could be wrong, I don't know a lot about 620s, they made a lot of changes to that truck over its 8 year run.

Share this post


Link to post

wayno my info shows only one part number for the 620 trans mount. So it appears it was used with the 71B and the earlier F4W63L  I know the '73 uses a transmission almost identical to the 510.

 

I guess for $17 you could find out. The 510 uses a different number than the 620. So it may bolt to the trans but not the cross member?

Share this post


Link to post

Every 1972 620 I have ever seen looked exactly like a 521 except for the body shape, but I have concluded that other stuff had changed that is not so easy to see, like the transmission cross member, 521s didn't have a removable cross member, but I guess all the 620s did have a removable transmission cross member, so that may have been when they switched over to the better transmission mount.

I obviously have never owned a 620, but I like heads they came with, a nice assortment to pick from, a head for every application.

Share this post


Link to post

The 620 cross member simply needs to be rotated 120. This moves the mounting bolt holes farther to the rear for the longer 71B transmission.

 

wayno here is my trans mount for a 710. It uses the F4W63L, similar to the 510. Probably similar to the 620, 610 and the A10s that all used this transmission

 

HnB6kdV.jpg

Share this post


Link to post

s-l1600.jpg

Close. It's not a Nissan part only made to fit a Nissan. The 720s all used the 71B.

Share this post


Link to post

So based on what I read, the mount won't fit correctly. What would the difference in mounting be? The mount won't mate to the transmissiin or to the crossmember?

Share this post


Link to post

So I can only assume this is the mount ..

 

Screenshot_20171108-135000.png

Do you have the original that goes to the vehicle?

I am using that exact same mount in datzenmike s post..... it fit the transmission but not the metal mount in my 521.... maybe its the same deal.....

Might be something where you can drill new holes in the cross member and it will all bolt up....

I would be happy to get some measurements if your interested....

Share this post


Link to post

Can you post any pics of what your looking at or for... maybe a pic of the cross member too...

Share this post


Link to post

I think they will all fit the transmission OR all 71B will and all F4W63 and F4W63L will. Differences, if any, will be the mount to the crossmember bolt pattern.

Share this post


Link to post

I think they will all fit the transmission OR all 71B will and all F4W63 and F4W63L will. Differences, if any, will be the mount to the crossmember bolt pattern.

That's what I was thinking.... don't know how that cross member is set up....

If the mounts are the same height it should be just a matter of drilling new holes in the crossmember

Share this post


Link to post

Height is another thing. Higher or lower affects the drive shaft angles and may introduce vibration. When I swapped a 71B 5 for my F4W63L 4 speed the back of the shifter was above the tunnel sheet metal. Maybe 3" higher using the 710 rubber mount. I had to section and lower the crossmember.

Share this post


Link to post

I'll make sure to post a picture tomorrow of the cross member, can't do so right now since the car is in a different location. Also i'll make sure to get the serial number of the transmission as to further help you guys out. I also believe if I am not mistaken, that the datsun roadster 4 speed has the same transmission but with a different bell housing. Which made me guess that the Chevy mount that the roadster owners use might also fit the 510 with the drilling of new holes in the cross member. As far as height difference goes, I don't see how some washers couldn't compensate the difference. 

 

Link to the Chevy transmission mount guide. http://www.311s.org/pmwiki-311/pmwiki.php?n=TechSection.ChevyTrannyMount

Share this post


Link to post

That definately looks like a good option... basically anything that holds the transmission in the proper location will work....

Share this post


Link to post

The 510 transmission is a F4W63. 26" long, speedometer drive on the rear left side. Two part aluminum case with bolt on oil pan with drain. Front case has a waffle pattern on it. Sedans have a slightly closer ratio gear set than the wagons.

 

I believe the Roadster 4 speeds are longer.

 

Washers won't help if the new mount is too tall. Generally if it fits (or can be made to fit) and does the same job... good enough.

 

Do you have the old one?

Share this post


Link to post

No, sadly the previous owner didn't give me the transmission mount, just the cross member. I have a roadster transmission laying in my parts stash and I thought that one had a mount I could steal from it and to my surprise it was also missing it. x.x  

He also forgot to give me the throttle linkage that hooks to the carb, and $100 for a new one feels like a lot tbh. :o

Share this post


Link to post

Doubtful a Roadster mount would be the same as a 510. Often the transmission is used in many applications. It's easier to engineer a mount for each vehicle than to modify each transmission.

Share this post


Link to post

The Roadster mount bolts to the cross member are 4 inches apart center to center, they are almost as far apart as the mount pattern to the transmission.

  • Like 1

Share this post


Link to post

Well just found out that the transmission mount holes are the same, but the crossmember mount holes aren't. Which means the chevy mount works, but it will need to be adapted to the cross member like the roadster one too. To my luck the previous owner has the original 510 tranmission mount so I'll be picking it up tomorrow from him.

Also my flywheel has A67 written on it I believe. What does that mean? I also placed a 510 clutch on it to see if it was the same size as the matting surface and it seems to be spot on. The L20B came with a W58 head and I think someone on here said it usually comes with a 200mm flywheel.

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×

Important Information

By using this site, you agree to our Terms of Use.