Hi All.
I'm just buttoning up my clutch replacement on my 350 4-speed.
Also replaced the engine mounts and trans mounts while I was at it.
The speedo cable was pretty chewed up and had melt damage from years of abuse and poor routing near the exhaust, so I decided to replace it and the "bullet" that retains the speedo gear in the trans.
Unfortunately (and so typically for me), when replacing the bullet, I let the plastic speedo gear drop down inside the tail housing of the trans and now it's out of reach entirely. UGH!
So - A couple of questions:
- Are there any tricks to try and fish the gear out of there without dropping the whole trans again and pulling the tail housing off to retrieve it?
- Would it be 100% a Bubba move to just leave it in there and replace it with a new gear? Is there enough going on in that area of the trans that it could chew up the plastic gear and do damage to the trans?
- If leaving it alone is an option, which type of gear do I need to replace it? I've got the original Muncie Diff still with 3.36 gearing and non-Posi.

Thanks!

 

get a grabber you can get it out I had one do that and I got it out,,, also if you need a new gear you can go to most gm dealers and they still have them

 

Just drop some ball bearings in there it will bust up the plastic gear and you won't have to worry about it.



Seriously, though. get the tool forman showed. I have one and it's an indispensable tool to have around the shop anyway, even if you aren't successful retrieving the gear.

 

I'd get it out of there! Unless your not concerned about bits of plastic getting ground into your syncrlos .

 

Well, I'm about out of ideas.
I tried the pickup tool but that doesn't seem to be flexible enough to get around the corners or into the nooks where this bugger might be hiding.
I even got my little boroscope out to see if I could see where the gear had fallen, and no sign of it.
I got a small length of bare copper wire, bent a hook on the end and tried to fish it out, also no-go.
I'm one step away from dropping the trans again, but it was such a bear to get it mated back up with the new clutch that I'd hate to go back to square one. Plus I would still likely need to drain out the fluid, crack it open and remove the tail housing to retrieve the escaped gear.
What other ideas am I missing?
What would the real risk of just leaving the old gear in there and just replacing it with a new one? Is the fluid well in the tail housing connected directly to the main reservoir? There's a bit of a shelf cast into the inside of the tail housing that this gear may have snuck underneath. See photo of an eBay listing part.
if it got chewed up, where would it get caught up in? And then what damage would ensue from the plastic remains?
thanks!

 

Have you tried a bore scope camera? If you can located the part, chewing gum may be used to grab that bugger. Good Luck. Have you done any Google Searches?

 

Not an expert but I would think there is the real risk of it pulling a chunk in between two gears and breaking the case.

 

OK - I retrieved the offending AWOL speedo gear, but I ended up having the drop the trans again and crack open the rear housing seal to allow it to fall out on the floor. Here's a picture of it. I haven't counted the teeth yet, but what color would you say this was originally? I'm having a new kit shipped with 5 or 6 gear options, the bullet housing and the bolt and keeper.
I've also ordered a new set of seals for the side cover, the rear housing to the main casing, the 3 shifter control shafts, and the rear output shaft seal.

So, now I've got a few questions:
1) See the 2nd photo of a small spring-type part that also came out when I separated the 2 halves of the case. What does this guy go to? It's about 1.5" long and looks almost like my tweezers from my swiss army knife. I can't seem to locate this part in any of the diagrams of the M20 in exploded view. Could this have been sitting loose in the bottom of the fluid in the case all this time without any function?

2) Also, the rear housing case was able to be separated from the main shaft and main case without having the remove the reverse lever, even though instructions showed that I needed to punch out the keeper pin on the outside of the case to allow the reverse lever to be pulled partially out. Since it came apart without this, will I be able to re-assemble the case halves together without retracting the reverse lever? I'm not excited about trying to hammer out that keeper pin with a punch, as it looks like there may be a hairline crack starting on the "boss" that forms around the reverse lever hole.

3) My M20 has a plastic speedo gear on the tail shaft, similar to the driven speedo gear (see 3rd photo). Is this normal? Shouldn't there be a metal gear there? Or am I ok to leave the plastic (looks like Nylon) gear in there? It appears to be in decent shape.

4) Going back to the initial problem that caused this repeat of the trans drop and now dis-assembly, what is supposed to keep the speedo driven gear inside the bullet? Looks like you pre-feed the gear into the nose of the bullet and then thread the bullet into the rear housing hole, then the tip of the gear nests in a hole in the opposite side of the casting. Only problem was in removing the bullet, the gear stayed put, and then fell down into the casing. What should I have done to avoid this??

5) What caused me to want to pull out the bullet and the gear originally, was that the new speedo cable I bought from Corvette Central seemed to have an internal cable that was slightly too short, and wouldn't engage fully into the square hole in the driven gear shaft. The overall cable length was maybe a foot too long, and I think maybe the extra twists and turns I made to take up the extra length may have made the internal cable retract a bit within the jacket. My original cable is a little over 70", but the new one was a bout a foot longer (of course I forgot to measure it before I routed it in the car. Approximately how much of the square cable should be exposed outside the trans-end fitting when you go to engage it into the speedo gear?

6) LOL - Anyone know how to get trans fluid stains out of garage floor cement?

 

Answered my own question #1. The spring thingy in the 2nd photo is just part of the "claw" part that must have come off the grabber tool I was using to try to retrieve the speedo gear originally.
That is a major relief.

 

I had a similar experience with a recent reproduction speedo cable. Does the inner cable seem to be the right length when the cable is laid out straight? Appears to withdraw into the casing as the cable is bent? Something odd going on with the casings being made today. I have two older cables which do not do this. I recently removed a new speedo cable which disengaged completely during installation. Put the old one back. At least my speedo registers. Picked up a NOS cable which I will try some time in the future.

Ive been burned several times recently with reproduction parts of poor quality. Try to stay with original parts or NOS when they can be found. Otherwise we’re left to make the best of what is offered. Sometimes there is no other option.