50 replies to this topic

[Tom Hampton]

Ah, Ha, but we have made others un-pi$$ed off.

+1

[SaulSpeedwell]

The inthusiasts manual was the best 40.00 I ever spent.

I will do a write up in word with pictures , I will bounce it off of you guys to see it I hit the high points. I can point out how the 99 differs slightly than what is depicted in the manual. I will also show the tools And how to make them.

I have found that a weak point in this trans. Is the rev gear and synco.

Most of the transmissions I see run in your neck of the woods. The reverse sleeve is frequently worn on street trannies, but I don't think I've ever seen it need addressed a second time. There may be something particular you are doing in the driver's seat, or something wrong in the stackup of that particular box.

Having said that - the 99+ trans doesn't deserve its "better than the others" reputation. The 5/R springs (and thus the syncros and hub sleeves) seem more prone to failure, possibly because the 99 shifter has less "give" in it.

The syncro springs are the big reliability issue in these boxes - improved parts would be a nice thing. The rapid wear of the shift rod ends can be addressed with heat treatment.

[FTodaro]

Adax thanks for the post, you still enlightened me. I agree on the clip pliers I have been using those cheap deals and they either destroy the clip or take for ever to remove.

I was going to post the pictures of the tools first and how to make them, I just spent the day doing a motor swap for a buddy.

In examining this transmission we found some strange damage to the 3/4 shift hub. I have posted a pick. In talking to Carl Z. about it he has not seen it before. I am wondering if if this kind of damage came from towing/trailering the car in gear. Take a look tell me if you have see this kind of wear on the shift hub?

[SaulSpeedwell]

That's normal wear from going into/out of 4th (and getting on/off throttle/brakes in 4th). A worn/damaged sleeve exacerbates this wear - when the sleeve is perfect, the wear is maybe 10-20% of what you show. Towing in 4th gear a significant amount of miles could make similar marks, but throttle and braking are larger loads to those surfaces.

The hub is not hardened, you can file the high spots away and use a new sleeve if budget or parts availability/time require the shortcut.

The track makes a difference - Nelson Ledges and BeaveRun boxes will have more 2/3 wear, Mid Ohio boxes have more 3/4 wear.

[FTodaro]

That's normal wear from going into/out of 4th (and getting on/off throttle/brakes in 4th). A worn/damaged sleeve exacerbates this wear - when the sleeve is perfect, the wear is maybe 10-20% of what you show. Towing in 4th gear a significant amount of miles could make similar marks, but throttle and braking are larger loads to those surfaces.

The hub is not hardened, you can file the high spots away and use a new sleeve if budget or parts availability/time require the shortcut.

The track makes a difference - Nelson Ledges and BeaveRun boxes will have more 2/3 wear, Mid Ohio boxes have more 3/4 wear.

So I take from you post that i need to do something, ether replace the hub or its components or file down the high spots?

[dstevens]

Great news Dave!! Gotta be a tremendous relief.

Thanks Chris. I'm in as much (relief) shock now as I was then of what might happen. I did my first workout in about a year. A 500 meter pool run/walk. I'm WAY out of shape. Kicked my butt.

[dstevens]

Adax thanks for the post, you still enlightened me. I agree on the clip pliers I have been using those cheap deals and they either destroy the clip or take for ever to remove.

The Knipex tools are quite nice. Like German Mac or Snap On. Are those not just regular "horseshoe" type retaining ring pliers of good quality? I don't see any in the Snap On catalog but Mac has a set. http://www.mactools....ing-pliers.aspx Is there something about the head or mechanism of the Knipex that makes it a better choice than a similar tool of the same quality? My local industrial hardware joint has Knipex in stock but don't know about that one. A good set of horseshoe ring pliers are going to be at least 50-60 bucks and whatever tax and shipping.

Gotta get the car back together so I can do a couple of solos before my Mazdaspeed expires in Jan.

On edit: Sorry Adax, at Amazon, in stock....

[Adax]

On edit: Sorry Adax, at Amazon, in stock....

Well, can take some solace in knowing that I have the rare angled version with red handles. I'm sure they are light-years ahead of the straight version both in quality and function.

Since were are getting further off topic, I'll post up some images of a 4th syncro failure I recently had tomorrow for opinion.
Alan

[SaulSpeedwell]

So I take from you post that i need to do something, ether replace the hub or its components or file down the high spots?

If you were happy with how it went into and out of 4th gear before, you will still be happy now even if you do nothing. One tow home in 4th gear didn't make that wear.

If budget is no issue, you can replace the hub and it will snick into and out of gear a little smoother, but it isn't necessary and won't cause any reliabiliy problems. Quickly running a file over the burrs in each spline wouldn't hurt - the new sleeve is going to deburr things automatically,so you might as well do it now and avoid the debris from being in the reassembled box.

If we can get the springs to last, then we won't dent and crack syncros, and then we won't wipe out hub sleeves, and then we won't damage the hubs and gears. I'm starting to think "new" springs don't last as long as proven (de-stressed?) old springs.

[Bench Racer]

If we can get the springs to last, then we won't dent and crack syncros, and then we won't wipe out hub sleeves, and then we won't damage the hubs and gears. I'm starting to think "new" springs don't last as long as proven (de-stressed?) old springs.

IIRC, Jesse Prather of Prather MotorSports has fabed new springs for production car transmissions & the new springs continue to be an issue.

[FTodaro]

If you were happy with how it went into and out of 4th gear before, you will still be happy now even if you do nothing. One tow home in 4th gear didn't make that wear.

If budget is no issue, you can replace the hub and it will snick into and out of gear a little smoother, but it isn't necessary and won't cause any reliabiliy problems. Quickly running a file over the burrs in each spline wouldn't hurt - the new sleeve is going to deburr things automatically,so you might as well do it now and avoid the debris from being in the reassembled box.

If we can get the springs to last, then we won't dent and crack syncros, and then we won't wipe out hub sleeves, and then we won't damage the hubs and gears. I'm starting to think "new" springs don't last as long as proven (de-stressed?) old springs.

Educate me, what "springs" are we talking about? The little wire springs on each inner side of the clutch hub? Or?

I did not own the transmission before. I purchased it from someone with the intention of a rebuild for a spare, I asked about the history but he did not know much about it. I am going to try a light file, the metal on that sleeve is real soft so it will not take much work to clean it up.

[Adax]

I had what I would consider an odd 4th gear syncro failure a few months ago. I had a bout 3 weekends on a recently rebuilt tranny with all new syncro rings (among other things). It rather suddenly started grinding going from 3 - 4 when shifted quickly. On disassembly, the 4th ring seemed to be stretched for lack of a better word but all dimensions were essentially the same as a new one. As you can see in the first image (damaged syncro), as compared the the second (new syncro), the old one sits further down on the 4th gear cone or boss.

I most want to know if I did this somehow during assembly. Is a clearance off or could it be damaged when the front main shaft bearing is driven home along the input shaft?


Old




New






Here's my tube wrench I mentioned earlier




Thanks for any help.

Alan

[SaulSpeedwell]

Educate me, what "springs" are we talking about? The little wire springs on each inner side of the clutch hub? Or?

I did not own the transmission before. I purchased it from someone with the intention of a rebuild for a spare, I asked about the history but he did not know much about it. I am going to try a light file, the metal on that sleeve is real soft so it will not take much work to clean it up.

Right, there are two square wire springs per hub (6 total in the trans). These support the syncro keys (3 PEZ-candy shaped things per hub) which keep the rings aligned and transmits the shifting force against the ring so it can do the clutching necessary for the rev-matching.

The great majority of the trannies that have a "grinding" complaint will have a cracked syncro, and the great majority of those cracked syncros will have been caused by a syncro spring failing.

Each spring has a 90 degree bend where it locates in the holes in the hub - the bend being a severe stress-riser, this is where the spring ALWAYS breaks - and soon after, the spring "walks" around the inside of the hub until a syncro key is dislodged, misaligned, jammed, etc. Syncros will show dents near the key slots and eventually crack.

When a box suddenly goes from being fine to grinding each and every time, you can be assured the syncro has cracked. If you do not take it out immediately, the hub sleeve will get wiped out, followed by the gear itself.

The spring problem should be relatively easy to solve ... but there isn't much incentive for someone to solve it.

[SaulSpeedwell]

I had what I would consider an odd 4th gear syncro failure a few months ago. I had a bout 3 weekends on a recently rebuilt tranny with all new syncro rings (among other things). It rather suddenly started grinding going from 3 - 4 when shifted quickly. On disassembly, the 4th ring seemed to be stretched for lack of a better word but all dimensions were essentially the same as a new one. As you can see in the first image (damaged syncro), as compared the the second (new syncro), the old one sits further down on the 4th gear cone or boss.

I most want to know if I did this somehow during assembly. Is a clearance off or could it be damaged when the front main shaft bearing is driven home along the input shaft?

Here's my tube wrench I mentioned earlier

Thanks for any help.

Alan

What does the ID of the syncro ring look like? The rings are not very "stretchy" ...do the fine line in the ID look "melted" at all?

How did you get the 4th gear/clutch spline/bearing re-mated with the bellhousing? It sounds like you drove the bearing on last? I leave the bearing installed on the gear and push the assembly into the bellhousing. I tried it the other way once and "never again".

Outside possibility: I once had a syncro that fit and looked fine under hand assembly, but wasn't good once the box was installed. Did the same thing yours is doing. The internal "cone" was too steep for the cone of the gear it was mating to. Afterwards, it looked obviously "melted" on the ID, though. My hypothesis is it was a mispackaged part (from a different year? from a B2000 box?) rather than a manufacturing defect.

[SaulSpeedwell]

Please don't be insulted, but have you pulled the syncro ring apart wishbone-style? Sometimes a crack is hard to see.

[FTodaro]

Right, there are two square wire springs per hub (6 total in the trans). These support the syncro keys (3 PEZ-candy shaped things per hub) which keep the rings aligned and transmits the shifting force against the ring so it can do the clutching necessary for the rev-matching.

The great majority of the trannies that have a "grinding" complaint will have a cracked syncro, and the great majority of those cracked syncros will have been caused by a syncro spring failing.

Each spring has a 90 degree bend where it locates in the holes in the hub - the bend being a severe stress-riser, this is where the spring ALWAYS breaks - and soon after, the spring "walks" around the inside of the hub until a syncro key is dislodged, misaligned, jammed, etc. Syncros will show dents near the key slots and eventually crack.

When a box suddenly goes from being fine to grinding each and every time, you can be assured the syncro has cracked. If you do not take it out immediately, the hub sleeve will get wiped out, followed by the gear itself.

The spring problem should be relatively easy to solve ... but there isn't much incentive for someone to solve it.

Ok I am on the same page, I know to check those carefully. and I know the fail at the 90 degree bend. On the one I am rebuilding now I ordered all new. the current ones were not broke. I hope its the right move to go to the new spring vs. proven spring.

[FTodaro]

Alan, I would have to check my notes but I know that the reverse syncro is almost the same size as either the 3rd or 4th gear syncro and when you order them if you not careful you can mix them up. I do not know if that was it but I know they look the same size but they are not.

[Adax]

Alan, I would have to check my notes but I know that the reverse syncro is almost the same size as either the 3rd or 4th gear syncro and when you order them if you not careful you can mix them up. I do not know if that was it but I know they look the same size but they are not.

Checked that, it's a 3/4 syncro (it's R and 5 that are easily confused)

Please don't be insulted, but have you pulled the syncro ring apart wishbone-style? Sometimes a crack is hard to see.

Not at all, but yes, I stressed it and there are no cracks

What does the ID of the syncro ring look like? The rings are not very "stretchy" ...do the fine line in the ID look "melted" at all?

It looks normal to the naked eye, not the typical melted look of a worn one. I haven't tried magnification but I will.

How did you get the 4th gear/clutch spline/bearing re-mated with the bellhousing? It sounds like you drove the bearing on last? I leave the bearing installed on the gear and push the assembly into the bellhousing. I tried it the other way once and "never again".

Yes, I drove it on last. I've tried putting it in the housing but of course the input shaft pushes it out.

Let me make sure I'm getting this. So you put the bearing on the input shaft, push it through the housing with everything else by tightening the external housing bolts, then apply the external bearing snap ring? Is there a "stop" on the shaft to know when you have it driven on far enough? Seems like it has to be pretty exact in order to get the bearing snap ring on, but if it works is certainly sounds like a less traumatic way of doing it.

Thanks for everyone's thoughts.
Alan

[SaulSpeedwell]

Yes, I drove it on last. I've tried putting it in the housing but of course the input shaft pushes it out.

Let me make sure I'm getting this. So you put the bearing on the input shaft, push it through the housing with everything else by tightening the external housing bolts, then apply the external bearing snap ring? Is there a "stop" on the shaft to know when you have it driven on far enough? Seems like it has to be pretty exact in order to get the bearing snap ring on, but if it works is certainly sounds like a less traumatic way of doing it.

Thanks for everyone's thoughts.
Alan

I leave the front bearing on the 4th gear/input shaft the whole time. On disassembly I pull the bellhousing off leaving the bearing in place. Blah blah rebuild everything. Then, on final reassembly, the bellhousing is face down on the mother-in-law's heirloom cedar chest. I lower the assembled guts (with bearing still in tact on 4th gear) down "into" the housing. Only trick here is not letting 4th gear and syncro "walk" away from being properly clocked with their respective syncro keys. Light pounding on output end of main shaft using John Henry's rubber mallet until RTV squishes out and housings are touching. Lean trans back and peek into bellhousing, make sure nothing weird happened. You should see at least 1/2 of the snapring groove. If you see more, then 4th gear walked off the syncro keys and the bearing is pushed through the bellhousing too far. If you see less than 1/2 the snapring groove, then you need to pound a little more.

Then middle housing section, then shift rod ends and rollpins. Then "shift" the assembled tailshaft into "reverse" using a junk shifter or authentic Ethan Allen musket ramrod, and walk the tailshaft onto the rest of the assembly (hard to explain, easy to do once you are shown how). You will feel the shifter walk from "Reverse" to "Neutral" as you guide the shifter extension rod into the 3 shift rod ends. This avoids having to disassemble the tailshaft guts.

Flip trans on its back, with junk shifter supporting tailshaft so you don't get RTV all over the penthouse master bedroom carpet.

Now hit input shaft with a Mayan hand axe PERPENDICULAR to axis of shaft from 12, 6, 3, and 9 o'clock, thus walking the bearing that last bit forward. Now the whole snap ring groove should be visible. Put in snapring (using an 18th century speculum, of course). Hit the input shaft perpendicularly 1-2 more times while pushing on snapring if necessary.

The first time I rebuilt a trans I used the FSM and the "Enthusiast's Guide", destroyed some tools, at least two afternoons, much of my liver, and very nearly destroyed the trans as well.

I developed these procedures myself and have probably rebuilt 50 or so - if anyone has better / alternative methods, I'd like to hear them.

[dstevens]

Saul you rock! Great info.