5 speed disassembly questions

[matrophy]

Pulled z24 and 5-speed today hoping that the whining noise in my trans with clutch engaged that stops when clutch is disengaged is because of a bad main shaft front bearing or a counter shaft bearing or the pilot bushing. If either of these 3 aren't obviously bad, I'll take it in for a rebuild. I have a few questions that came up in the process:

 

 

 

1) I noticed some forward and backward as well as up and down play in the main shaft before I removed the snap ring. Not a lot of play but should it be moving it all?

 

1a) If there is play can it be blamed on the bearing or is it too early to tell until I get the two halves apart?

 

2) I have only removed the front cover and the 2 snap rings on the main shaft so far. I took a look at separating the two parts but ran out of time. Are there any secrets to separating the case or should it just come apart with a few taps?

 

3) I am pretty sure that this trans hasn't been worked on because the truck only has 67000 miles but the 2 halves of the case look like they are held together with grey silicone. I thought I heard that there was a gasket that is NLA now so if that's true then maybe the trans has been apart since it left Japan. Is it true that there was a gasket there at one time or maybe they used silicone at the factory? Neither here nor there but I'm just curious. 

Edited July 4, 2020 by matrophy

[Draker]

1. Yes there will be play. The input shaft is actually split after the first gear set. 
 

1a. Excessive play could very well be because of a bad bearing.

 

2. Front should come off easier than the rear. Try not to pry in between the mating surfaces. They are machined flat and damage will prevent proper sealing. Rubber mallet will be your friend. Some trannies have recessed area for tapping or prying. Rear half is usually easiest to remove in a specific gear as to move internal components out of the way allowing the case to slide off. Find the FSM for the truck and look at the MT section.

 

3. no gasket. Never seen one and I’ve opened several Datsun trannies. Machined surfaces so all you need is a good rtv. Honda bond, right stuff, Hyundai/Kia oem is what I use.

[matrophy]

Thanks for the concise answers. If the bearings or bushing aren't obviously bad, I'll need a rebuild. Do you know a good place in Eugene/Corvallis area?

[datzenmike]

Won't be pilot bushing. The pilot and the transmission main shaft are locked together when the clutch is engaged. (pedal up) Pilot can only possibly make noise when the clutch is disengaged (pedal down) and the engine and transmission are free to turn at different speeds. Always replace the pilot if you have the transmission out. It's easy and cheap $4.

[Draker]

56 minutes ago, matrophy said:

Thanks for the concise answers. If the bearings or bushing aren't obviously bad, I'll need a rebuild. Do you know a good place in Eugene/Corvallis area?

transmission solutions in Eugene is a great shop. It’s where all the local dealers and Indy shops bring trannies to for repair. I’ve had work done there. It is not the cheapest place, but it’s quality. Nice folks too and great warranties.

 

 

 

[Draker]

Once you pop it open you’ll be able to get a good look at the bearings. Removing from the center plate is a bit of a pain. I am in the middle of a countershaft bearing replacement myself. 
 

details on that are in my 1200 thread. 

[EDM620]

On 7/3/2020 at 7:03 PM, Draker said:

3. no gasket. Never seen one and I’ve opened several Datsun trannies. Machined surfaces so all you need is a good rtv. Honda bond, right stuff, Hyundai/Kia oem is what I use.

You shouldn't even use RTV on those machined surfaces. Some will squish out and end up free floating inside the transmission.

[datzenmike]

Nissan uses a neutral light gray color sealer. Permatex gray sealer is close. It's probably a form of RTV but not as gooey/stretchy when set. Use sparingly and join part and bolt up lightly finger tight, wait 10 min then torque to spec.

[matrophy]

On 7/3/2020 at 7:13 PM, Draker said:

transmission solutions in Eugene is a great shop. It’s where all the local dealers and Indy shops bring trannies to for repair. I’ve had work done there. It is not the cheapest place, but it’s quality. Nice folks too and great warranties.

 

 

 

I found a place in Coburg called Geezer Garage and I'm pretty impressed with them so far. They tore apart the tranny while I waited and couldn't find anything obviously wrong with the bearings but thought that the reverse idler gear (or gears) looked a little worn. They are going to do a rebuild and try and clean up the gears. Quote was $500 plus parts.

[Draker]

2 minutes ago, matrophy said:

I found a place in Coburg called Geezer Garage and I'm pretty impressed with them so far. They tore apart the tranny while I waited and couldn't find anything obviously wrong with the bearings but thought that the reverse idler gear (or gears) looked a little worn. They are going to do a rebuild and try and clean up the gears. Quote was $500 plus parts.

 

Good deal. Reverse wear is common because it doesn't use a syncro. I hope the find the source of the issue!

[matrophy]

2 minutes ago, Draker said:

 

Good deal. Reverse wear is common because it doesn't use a syncro. I hope the find the source of the issue!

After watching the guy tear the tranny apart, I'm glad I trusted my instincts and decided not to try it myself. Nevermind putting it back together. This guys has obviously been working on standard transmissions for probably 40 years and had it completely apart in 45 minutes.

[datzenmike]

1 hour ago, matrophy said:

I found a place in Coburg called Geezer Garage and I'm pretty impressed with them so far. They tore apart the tranny while I waited and couldn't find anything obviously wrong with the bearings but thought that the reverse idler gear (or gears) looked a little worn. They are going to do a rebuild and try and clean up the gears. Quote was $500 plus parts.

 

Just turn the reverse idler backwards and put back on. Only a C clip holding it on.

[Draker]

3 hours ago, matrophy said:

After watching the guy tear the tranny apart, I'm glad I trusted my instincts and decided not to try it myself. Nevermind putting it back together. This guys has obviously been working on standard transmissions for probably 40 years and had it completely apart in 45 minutes.

 

Impressive! sounds like he'll find the issue then.