5sp transmission rebuild

[69roadster]

The 1at an 2nd gear Synchro are shot in my transmission.  Is there anything special about rebuilding the roadster transmission, that would require a roadster expert or can I take it to my local transmission shop. 

How can tell what style transmission I have, as far servo or Warner

[notoptoy]

I would not take it to "any" transmission shop, even though there is nothing really unique. It is 50+ year old parts and not everyone has the experience or CARE to take the time to do it justice. I think you are better off boxing it up and shipping it too a roadster specialist who will be far more likely to use the correct parts and get it right the first time. Because you have to pull the engine to get the transmission, it really helps to know that it is good before you put it back together.

[jrusso07]

Hard to tell if its a servo or Warner box until you crack it open. Warner (brass synchros) are relatively inexpensive. Not so much on the servo synchros.

[david premo]

So rebuilding the servo transmission is a long job of continuous inspection for common problems from previous rebuilds. None of the transmissions I take apart now are first time rebuilds so you’re typically looking for all the previous rebuild mistakes. Looking inside the drain plug you can decide if you’re working on a servo or Warner transmission. Observer the synchro you see via the drain plug hole, if you see only black steel it’s servo and if you see brass, then Warner it is. The other major issue to watch out for is cheep bearings when you go to rebuild the transmission. The world bearing supply is not as good as it was 30 years ago. Be sure to quality Japanese bearings only! You will need buy and make tools for removing and installing the bearings, otherwise you will damage the transmission taking it apart and the new bearings during installation.

Also taking it apart in a methodical method is important as all the snap rings come in multiple thicknesses to assure a proper fit of each item. So if you do have snap rings that are not the correct thickness then you will need to track some down. The 5th gear and the main-shaft nut or nuts is another issue, the 5th gear come in two styles the late splined ones and early smooth press-fit which will need to be welded. The main shaft single nut which is by far the more common needs to have a tack weld in just one spot after it has been tightened to the correct torque specifications so it will not back off under load. And then there is the end-play of the input shaft and the alignment of the countershaft to the main-shaft, when reassembling the cases.

So to put a timeline on the job, it’s about 9 hours or work once the transmission is out of the car and on the work bench until you close it up and that’s if you don’t have any major problems. If lucky enough to own a set of The Datsun Roadster Book by Scott Sheeler, “part 2” book pages 62-69 describes how to take it apart and reassemble the transmission in a proper sequence. I’ll be honest, rebuilding a Roadster 5 speed is a very involved and long job, not to be taken lightly. If you’re not ready to tackle this then consider contacting in no specific order one of the following people, Steve Pettersen, Stan Chernoff, Ross Mullin, Rallye Roadster for an exchange rebuilt transmission or to have your transmission rebuilt.
Dave

[notoptoy]

To Dave's point, I did tackle my own transmission, with help from the Sheeler book, which is good (But has at least one critical mistake). It took me way, way more than 9 hours, and I bought a lot of tools (which I like to do anyway) including an assortment of large snap ring pliers, various bearing pressing accessories, and two giant wrenches for the main shaft nuts, and then lots of parts from a local bearing house and the Roadster vendors. It took me multiple attempts (3 assemble and disassemble to correct attempts) to sort out all the issues, and was absolutely saved by feedback and pictures and instruction from the experts here on the forum.
In the end it works great, EXCEPT, I did something stupid with the friction bands, and now have to pull it apart and do it again. So, what am I saying? I enjoy a challenge - you may not. It was not more economical, time sensitive, nor delivered the best results that using a pro would have done. But, the next time, I'll do much better and might even justify the investment in the tools! (Right! )
Dave has listed the best options for getting it done right, don't waste your money or time with anyone not experienced with Roadster specific transmissions. It's a very expensive gamble to go elsewhere.

[Linda]

Skip Miller, Miller Sports and Imports, Pasadena, CA original Datsun mechanic, has done lots of these.
Linda

[Gregs672000]

Several years ago I was encouraged when I stopped by a local old timer trans shop and the owner came out and knew my car immediately as well as its known weaknesses with the 5th gear walking off. Turned out he used to race a 240 with the Roadster 5 speed.
I'll be taking my box to him this winter to go through.

[bikermike]

I know of 2 owners that have used Marin Autotrans in Novato, CA

[bakerjf]

I used Steve Pettersen in Chico. Knows every inch of these boxes, maintains all the parts in-house. Added bonus is if you drop/pickup the box yourself, he will gladly give you the tour of all the awesome projects he has going at any given time.

[69roadster]

I'm in the midwest. I'm going to call some of the places recommend. Also have to figure out shipping. The driving season here is almost over , going to pull the transmission when I put the car up for the winter

[vorpal]

Just had my 69 5 speed repaired by Bert's Auto & Transmission in Surrey, BC Canada through Ross Mullen's contact. Got it repaired, resealed and returned and installed it on the weekend... shifts great!

In July on a weekend event I noticed 5th gear was popping out and it would occasionally lock up hard into 1st and you would have to two-hand it out of gear... this all came on fairly suddenly, so under Ross's advice I parked it immediately and found these when we drained the trans prior to pulling it and the motor:



Looked into repairing it myself but decided against it based on my lack of transmission knowledge and accessible parts in my area. Boxed it up and freighted it 1000 KM to Vancouver and they found the 5th gear shaft loose and the locknuts backed off mis-aligning the shaft. They fixed that and as well as completed a grinding/dressing of gears & synchros, a bearing & seal kit and general cleanup, assembly & 3 qts of their recommended lighter weight Dextron fluid with a high level of friction modifiers. Total in was $ 1400.00 CDN + shipping.

I find it's now shifting more 'crisply' than it did before, and 5th has a better positive engagement feel when you shift into it.

[bakerjf]

Wow, sounds like a great deal!

[cole455]

[quote=notoptoy post_id=297783 time=1568476623 user_id=2256]
To Dave's point, I did tackle my own transmission, with help from the Sheeler book, which is good (But has at least one critical mistake). It took me way, way more than 9 hours, and I bought a lot of tools (which I like to do anyway) including an assortment of large snap ring pliers, various bearing pressing accessories, and two giant wrenches for the main shaft nuts, and then lots of parts from a local bearing house and the Roadster vendors. It took me multiple attempts (3 assemble and disassemble to correct attempts) to sort out all the issues, and was absolutely saved by feedback and pictures and instruction from the experts here on the forum.
In the end it works great, EXCEPT, I did something stupid with the friction bands, and now have to pull it apart and do it again. So, what am I saying? I enjoy a challenge - you may not. It was not more economical, time sensitive, nor delivered the best results that using a pro would have done. But, the next time, I'll do much better and might even justify the investment in the tools! (Right! )
Dave has listed the best options for getting it done right, don't waste your money or time with anyone not experienced with Roadster specific transmissions. It's a very expensive gamble to go elsewhere.
[/quote]

Sounds like you learned a ton about them! Also, there’s a guy that rebuilds roadster transmissions just off Shattalon.

[redroadster]

Idealy you would want a complete 1st / 2nd sycro assy.
& Both 1 & 2 speed gears , possibility a shift fork
What was it doing hard to get into gear ?

[notoptoy]

To Dave's point, I did tackle my own transmission.........It's a very expensive gamble to go elsewhere.

Sounds like you learned a ton about them! Also, there’s a guy that rebuilds roadster transmissions just off Shattalon.

Cole - who is that? You??