Transmission Check over, two a523's for different purposes.

[DoubleD]

I am not sure how to title this. My friend bought an A523 at the junkyard a year ago, I am going to help him go thru it to check it over. This will be being installed into a decently powered Holset fed Spirit R/T. The transmission in question is of unkown miles and origin to me. We are planning to go through it, replace what is worn and put it back together and put it in his car with a new clutch.

When going through an a523, what should I be looking for, what wears out, what needs replacing. I was thinking replacing all seals would be a smart idea. I did already pick up a set of Lengel's bronze for pads for this build. What should I be looking for? I have never rebuilt a transmission in my life.

Secondly, after going through this transmission, I plan to go through my own which is also a a523, using this one as a guinea pig first. What needs to be done to this transmssion to handle big power in my IROC R/T? (500whp)
My transmission is out of a 93 Shadow that was recently rebuilt before I got it, shift flawlessly right now.
I talked to Jackson and I am going to have the front case bearing on the main shaft welded to the shaft. I am also installing a set of Lengel's bronze fork pads, but this one is also getting an OBX installed. I will also replace all the seals on this one too. I think this should wrap up any weaks parts of this transmission, but what else needs attention?
Thanks

Forgot to mention, I'm adding drain plugs to both transmissions when they are apart.

[cordes]

If you're checking out the sleeve on the main shaft that's the biggest concern IMO. Other than that make sure that the bearings and the teeth on the synchros and gears look decent. IIRC factory spec is 50% of the teeth left but I wouldn't put a gear back in that is so worn.

[Ondonti]

I worry about how much "wear" is left on the synchros to gear friction surface. You should be able to check with a feeler guage but I have never seen anyone share any numbers like I have seen for other transmissions. When synchros get too worn, they bind up on the gear instead of functioning.

[DoubleD]

If you're checking out the sleeve on the main shaft that's the biggest concern IMO. Other than that make sure that the bearings and the teeth on the synchros and gears look decent. IIRC factory spec is 50% of the teeth left but I wouldn't put a gear back in that is so worn.

I just read through the entire FSM I have on the 523/568, there is no mention of a sleeve on the main shaft. I also find no text on measuring the synchros and what is acceptable. I will look at them, see what condition they are in and possibly post pictures.

I worry about how much "wear" is left on the synchros to gear friction surface. You should be able to check with a feeler guage but I have never seen anyone share any numbers like I have seen for other transmissions. When synchros get too worn, they bind up on the gear instead of functioning.

How would I check this? I understand how to use the feelers, but where am I checking for a thickness?

Also picked up a Miller tool 6252 on eBasy this morning for cheap, should help on the tear down as the only "difficult" tool to replicate.

Thanks

[cordes]

I was talking about the sleeve that you're going to have tacked which the bearing rides on.

[DoubleD]

Ahh ok, I re-read through my FSM again. So I am going to be welding the inner race of the front intermediate bearing to the shaft. I will check over the bearing and race on both transmissions for wear since this seems to be a common failure point. I found JT's build log, that explained a lot.

[2.216VTurbo]

If you're checking out the sleeve on the main shaft that's the biggest concern IMO. Other than that make sure that the bearings and the teeth on the synchros and gears look decent. IIRC factory spec is 50% of the teeth left but I wouldn't put a gear back in that is so worn.

In my experience this is a big issue on the 555's(especially early build units) but not as much on the 523/568's. Definitely worth a look tho.

You're not planning on putting 500HP thru one axle are you Double?

[135sohc]

I worry about how much "wear" is left on the synchros to gear friction surface. You should be able to check with a feeler guage but I have never seen anyone share any numbers like I have seen for other transmissions. When synchros get too worn, they bind up on the gear instead of functioning.

Nobody shares the numbers because there are none. I have the factory training literature that the dealership techs would have used back in the day to service these things and its very lacking of detailed information like that. It says that if there are complaints about hard shifting/clashing then you should just replace the synchronizer rings and if that doesn't fix the problem then replace the gear and synchronizer.

[DoubleD]

In my experience this is a big issue on the 555's(especially early build units) but not as much on the 523/568's. Definitely worth a look tho.

You're not planning on putting 500HP thru one axle are you Double?

No, the built up transmission will be treated to an OBX. No more one tire fire.

[135sohc]

Get a set of lock ring pliers also. Not snap ring.

http://www.sears.com/craftsman-lock-...p-00947386000P

[Lotashelbys]

How would I check this? I understand how to use the feelers, but where am I checking for a thickness?

Also picked up a Miller tool 6252 on eBasy this morning for cheap, should help on the tear down as the only "difficult" tool to replicate.

Thanks

Message me for the specs on the distance from your brass stop rings to the speed gear measurements on 3-4-5. There is a certain window I have found that will tell you if it will grind or not... For the 1-2 I always flip the entire synchro assembly around so the 1st gear side now is used on the 2nd gear side. Usually the 1st gear side has much sharper sleeve teeth and more fiber left of the catch rings...

[Ondonti]

Nobody shares the numbers because there are none. I have the factory training literature that the dealership techs would have used back in the day to service these things and its very lacking of detailed information like that. It says that if there are complaints about hard shifting/clashing then you should just replace the synchronizer rings and if that doesn't fix the problem then replace the gear and synchronizer.

I did find it interesting looking at rebuild videos in 2013 where other transmissions have posted clearances so you know when your synchro is too worn. Not much help when the parts don't exist to slap in new synchros at every complaint.

Message me for the specs on the distance from your brass stop rings to the speed gear measurements on 3-4-5. There is a certain window I have found that will tell you if it will grind or not... For the 1-2 I always flip the entire synchro assembly around so the 1st gear side now is used on the 2nd gear side. Usually the 1st gear side has much sharper sleeve teeth and more fiber left of the catch rings...

...

[BadAssPerformance]

I found JT's build log, that explained a lot.

Always glad to help! Let me know if you have questions.

Get a set of lock ring pliers also. Not snap ring.

http://www.sears.com/craftsman-lock-...p-00947386000P

^^^ THIS... I need these. I've used snap-ring pliers for years and have tricks to make them work and even modified one... but he's right, these will work a ton better

[135sohc]

Those need some minor file fitting to reach down inside that recess for the big snap ring that locates the sealed ball bearing otherwise they are good for the money spent. Those won't slip and you get better control so the risk of over expanding and ruining the retaining rings is greatly reduced.

[Lotashelbys]

...

lol sorry Brent I will get the numbers for you to go off of if I remember next time im in my shop. I have them written down with all my trans tools and such. I have measurements with an NOS 3-4-5 stop ring to speed gear and a few that I kept that did grind. They are really close from one gear to another so it should work for most anyones. They were like + or - .002

[Ondonti]

lol sorry Brent I will get the numbers for you to go off of if I remember next time im in my shop. I have them written down with all my trans tools and such. I have measurements with an NOS 3-4-5 stop ring to speed gear and a few that I kept that did grind. They are really close from one gear to another so it should work for most anyones. They were like + or - .002

Visit the shop? What about 1st & 2nd? I don't even know how you would measure those.

[Lotashelbys]

Visit the shop? What about 1st & 2nd? I don't even know how you would measure those.

Yes,just finished another trans. I checked an NOS 3-4-5 stop ring on 3 different speed gears and got a measurement of .057-058". Thats using a feeler gauge measuring the gap between the machined flat area of the stop ring and speed gear when its completely seated on it dry. Now one used rings you will have to file the surface flat again before you measure that gap. I have a ring I kept that was known to grind just to measure the difference and that one is around .045" I have noticed anything under .050" will be questionable and I would not run them. On worn rings if you shine a light on them just right you can see just how "flat" the inner teeth have become. An NOS one has nice shape teeth that look like alot of triangles all lined up. Wore ones look more like a trapizoid and they are usually worse on the ones closest to the machined flat or rear of the ring.

I can get you measurements on the 1-2 stuff also but they are usually in good enough shape on both sides. Usually what happens there is the 1-2 pad is burned up.

[Ondonti]

Yes,just finished another trans. I checked an NOS 3-4-5 stop ring on 3 different speed gears and got a measurement of .057-058". Thats using a feeler gauge measuring the gap between the machined flat area of the stop ring and speed gear when its completely seated on it dry. Now one used rings you will have to file the surface flat again before you measure that gap. I have a ring I kept that was known to grind just to measure the difference and that one is around .045" I have noticed anything under .050" will be questionable and I would not run them. On worn rings if you shine a light on them just right you can see just how "flat" the inner teeth have become. An NOS one has nice shape teeth that look like alot of triangles all lined up. Wore ones look more like a trapizoid and they are usually worse on the ones closest to the machined flat or rear of the ring.

I can get you measurements on the 1-2 stuff also but they are usually in good enough shape on both sides. Usually what happens there is the 1-2 pad is burned up.

I have one that sat and somehow the 1-2 rusted. This was evidenced by the 1-2 synchro assembly being seized together, car would lurch forward if you didn't hold the clutch in while starting in neutral. I cleaned it off and maybe removed even more material. Now the 1-2 are so worn that they stick onto the speed gear and get seized because they get crooked. No resistance at all to going into 2nd and it only shifts clean at high rpms. I skip the gear otherwise.
Really odd because this transmission was in a car, I have transmissions that were treated much worse.

[DoubleD]

Got the first transmission torn down last night, went fairly smooth other than removing the fifth gear on the input shaft, it was firmly on the splines.
Here is how the bearing race looks:

Does this look right? Has the race moved on the shaft? Getting ready to have the race welded to the shaft if everything looks right.
Photos of synchros to come..

[DoubleD]

Here's how the intermediate shaft looks.