So there I was cruising along on a nice sunny day and decided it'd be a good idea to get on it! So I do and run it up through 3rd gear and go to stop and try to down shift into 1st and hear this god awful grinding/rattling sound. So while in first I get it around a turn and come to a stop, take it out of gear and put it back in there and still makes that noise. Needless to say i put it in second and made it home. I was just wondering if the gear itself is out or just a syncro? When I was in the drive way It went into 1st just fine but i went to release the clutch there was nothing, no grinding/moving/anything. So i put it in second and called it a day.

 

You blowed up first gear

 

The gear itself or syncro? Is first gear linked w/ any other in the tranny? Cuz it went into reverse/2/3 I didn't try 4th though?

 

Syncro meaning brass , no its not the synchro. It could be the teeth inside the slider. If it is you can probably tell by rolling the car which will move the gears , let the clutch out if you get nothing it could be the slider teeth.
If its the teeth on the first gear gear you should get some more grinding.
If its the teeth on the counter shaft first gear gear you should get some grinding also because they rarely remove all the teeth from the gears.

power goes in the input shaft from clutch,takes a 90 into the countershaft,then into first gear gear on countershaft,another 90 up into first gear gear on the mainshaft and into the slider then into the mainshaft and then out to the driveshaft.
Hope that made sense.

 

regardless what gear it is you need to drop it and rebuild it. do it once, do it right.. best of luck..

 

well, right when it happened i was rolling and it made that grinding noise trying to get it into gear. Then when I was in the drive way i put it into first w/ ease and got nothing at all. I'm going to pull it regaurdless but i was hoping to buy a rebuild kit but i don't know if that'll work now. Does anyone have a site that offers parts? I checked w/ summit and they have a basic kit for like 140 bucks.

 

 

What does "do it right" mean? I know i need to beef it up a bit but I haven't found a upgraded kit for it. Do they make a better kit out there for these things?

And the teeth on the actual gear should be fine right? Just the brass/slider teeth are jacked up?

 

You are really guessing to what is broken inside. It could be simple but it could be teeth missing also. Get it out and open it up to see what damage has been done. Then you can see what needs to be replaced and rebuilt.

http://www.5speeds.com/

 

Not gonna lie guys but i have no idea when it comes to the inside of a tranny. Is there a plate or something that can be removed for me to see inside of her?

I really don't think its the gears. The car has been sitting the last 6 years and only 8k miles put on it the last 28 years. Also when i pulled the motor 2 summers back i pulled the tranny and changed the fluid. While draining it no metal came out of the fluid, except for very minor pieces on the plug which was nothing to worry about.

 

Yes you can remove the side plate cover and this will allow you to see inside at all the gears. It is going to be tough to do in the car but it is doable. You have to remove all the shift linkage and the exhaust might be in the way. The cover is on the drivers side of the trans and is held on by 7 or so bolts. The shift forks will come out with it so it has to slide out straight a little before you can drop it down.

 

Uhm...makes me wonder if some of you know anything about a muncie. All forward gears on the input shaft are always connected to the gears on the counter shaft...called a Synchronized Constant-Mesh Transmission. If any teeth on any forward gear have been wasted then you will have some grinding and/or it will feel like someone with a sledge hammer is banging on the drive train while you are moving...even if you have it in neutral. The reverse gear is different and slides into mesh with the countershaft while you are moving backwards (the reverse shift fork simply feeds the gear onto a worm gear ground into the output shaft).

If you were able to drive it in 2nd without any serious problems then it's more likely that the 1st/2nd gear shift fork and/or 1st gear synchro is damaged. However, you won't know until you take a look...like Gordonm said...remove the side cover.

In order to do that you will need to remove the shift rods. When you remove the cover make sure the shift forks come out with it...they are held onto the cover with a spring that you don't want to have pop out. The 1st/2nd shift fork will hit against the side of the housing if you have the tranny in neutral and will cause the shift fork to pop out and release the spring. Shifting into 2nd will line the fork up to slide out with the cover, so before removing the rods shift into 2nd and look at where the rear lever is then before removing the cover shift into 2nd. Also, a small hand mirror can help to see inside the housing better; though, if it's just the synchro dogs then you may not see anything at all...until you drain the lube, but you might find some metal shards stuck to the cover or can feel inside the housing for any metal bits.

You will need a bench press to complete an overhaul. If you don't have a press then you can still rebuild it yourself if you have a shop pull it apart and get a propane heater to heat up the parts which need to be pressed on...that's what I did. You may want to get the Overhaul Manual for your 73. There is an overhaul kit available and there's an Italian company that still has some gears for the muncies if you need a gear, but I don't remember where I got the kit or gears from and can't find my receipts.

A quick search of the internet found:

http://www.5speeds.com/muncie.htm

http://www.dandltransmission.com/muncie.html

Here's a nice picture of the spring on the cover:

 

No it won't be the brass.
Before removing the side cover push the rear lever forward putting the trans in 2nd gear,otherwise you'll leave the 1-2 fork inside the tranny.

 

Just another food for thought idea, but after my motor was rebuilt and I stuck the tranny back in I forgot to grease the pilot bushing and after a while it started acting similar problem to what your talking about. Or another idea is if it's a pilot bearing it could have failed or is failing, i've heard those have a tendency to from other people before.

This company has some upgrade kits, rebuild kits, and overdrive kits...I bought my O/D kit for my M21 there.

http://www.autogear.net/

 

Why , wouldn't the gear with the broken tooth have to be engaged to the mainshaft before you feel it ?
I've had trannys with a broken tooth on first gear and you wouldn't know it until you shift in to first gear.
I had one with "all" the teeth missing on the first gear countershaft gear, 4th,3rd & 2nd gears worked fine but you had no first gear.

 

Well...if "all" the teeth are missing then yeah...it won't move, but you will most likely have some crunching in every gear from large metal bits which are being picked up by the gear lube and wedged in between all the other gears...and in all likely hood it would only take about 4 feet before a piece gets wedged in another gear and everything locks up.

The "gears" are all engaged all the time. When you shift into a gear you are essentially sliding a synchro cluster onto the lower "dogs" (essentially small nodules like prongs which stick out from the lower section of the gear...not actual "teeth") of the gear on the input shaft which locks the input shaft onto that gear...the rest of the gears are spinning freely on the input shaft, but are constantly engaged with the coutershaft. So, even if the teeth are fine it's possible to break the dogs off the gear or synchro cluster so that when you put it into gear what's left of the dogs are scraping against the synchro and causing the noise, but the metal bits are smaller and made of a softer material and won't cause a significant problem for other gears.

 

Alright i started pulling it today...And I need about a 3/4 ft extension to get at those damn upper bellhousing bolts. Does anyone have any advise for me? or an easier way to get them out? Thanks

 

Why are you taking the bellhousing bolts out to get the transmission out. There are 4 bolts holding the trans to the bellhousing. These need to come out and the trans will come out.

 

Unless you have squashed body mounts,on those I have had to lower the input end and the bellhousing at the same time to get the trans out PITA.

 

Hmmm, i seen those but I didn't know if i could do it that way or not. I guess i thought i had to because when i pulled the 6sp in my camaro it was all one unit. And now that you think of it I think we had to loosen the motor mounts to get at the upper bell housing bolts. Now i'm excited and i'll get that bitch out in the morning. Thanks =)