Datsun Roadster Forum-311s.org

Changed out a 4-sp for a 5-sp tranny. Got all the requisite parts from the same donor car. Problem is in the install. After bolt-up, the motor mounts are stressed to a parallelogram shape. Ideas as to why or what I missed?

Background: The trannny mount to the cross member uses the new 5sp mount and old 1600 car cross member. Only see one way to bolt them up given the 2x 3-bolt pattern. The motor mounts are both shifted equally forward (about 1/2", up from the frame to the motor (ie motor isn't far enough back). However, the space between the tranny tunnel and bell hsg is only about 3/8". There is a space in the 2-part drive shaft couple...is that normal?

Thanks for the help

My 69 2000 did the same, I cut down a 4 speed mount to fit the 5 speed. Maybe the bolt holes are in a different spot front to back?
Anyone have both to compare?

I think you need to use the 5 speed crossmember and it should fix the problem.
Do you have any pics of the 1600 crossmember. I'm pretty sure that I have a 2000 crossmember laying around to check the difference.
Kevin

Are you talking about the drive shaft splins showing. Yes, you need some..so when the rear end moves up and down the drive shaft can go in and out. If thats not what you mean....my bad.

Richard

Tranny mount came supplied on the 5sp. I removed, wirebrushed, and painted it silver. It matches up a shoulder boss on the tranny. The cross member was in my car. Maybe the frame cross member for a 5-speed tranny is different?

That looks like a 4 speed crossmember, at least at that angle.
Photos here of my mount, a cut down 4 speed crossmember.
http://www.311s.org/pmwiki-311/pmwiki.p ... rannyMount

Yep thats a 4 speed crossmember the 5 speed is half as tall as the 4 speed the mount holes are most likely in the wrong place as well. Do you have the one for the 5 speed? If you do I would try it to see if it resolves your problems.
Kevin

Thanks for the replies all !
I guess I don't have a "5-speed crossmember" from what I'm reading (didn't know there was such a thing). The tranny mount is the right one tho, as I have the 4-speed mount and that ain't it.

Any pics available out there of the different crossmember from a 5-speed car?

This is a 4 speed cut down to 5 speed height. The strip of metal to the left is what was removed. The question is the fore and aft location of the holes.



Below is a 4 speed and 5 speed next to each other

Yup, the holes in the 4-speed crossmember mount will push the 5-speed forward. To use my 4-speed crossmember mount, I had to move the holes where the rubber mount drops in, further back.

23yrRebuild wrote:Yup, the holes in the 4-speed crossmember mount will push the 5-speed forward. To use my 4-speed crossmember mount, I had to move the holes where the rubber mount drops in, further back.

Looks like I need to drop the crossmember and get out the drill. Any measurements? We can get the info in one place and I'll update the WIKI post.

Dang, wanted to be done with it this weekend. Now it's cut-n-weld time.

Dims would be good if they are available

At least I can go tighted up the umpteen new Areoquip fittings on the Accusump in the interim.

What is the effect on the speedometer calibration if the 4-speed is swapped for a 5-speed?

Shannon

I have a NOS 5 speed crossmember in the garage. I can measure whatever you want. It won't be used by me, so I will probably put it on eBay.

What is the effect on the speedometer calibration if the 4-speed is swapped for a 5-speed?

Shannon

I had to change my speedo pinion gear to use with the 3.9 rear end.