So we found out why reverse doesn't work

Hexx · 12-22-2004, 10:14:00 PM

So check this out. My brother buys a Saginaw 4 speed manual from the junkyard last summer sometime (if I remember right...anyways last year sometime).

He wanted to take his auto out and put a manual in. After getting everything in and working he started having issues with reverse. He also had issues switching gears (not sure still).

Well, this winter he pulled the engine and tranny (and the whole front of the car off) to rebuild it all pretty much. Took the transmission apart to find metal at the bottom of it...oh noooz!

So, finally gets the gears out. Snapped a few pics this past weekend I was down there:

Can you guess which one is the reverse gear?

http://reno.sytes.net:8080/gallery/v...01&id=DSCF0264

Painted up tranny:

http://reno.sytes.net:8080/gallery/v...01&id=DSCF0268

Painted up motor:

http://reno.sytes.net:8080/gallery/v...01&id=DSCF0267

This is my brother's 78 Z28 he has been working on for the past few years...it is def coming together and is part of my insipration for mine:

http://reno.sytes.net:8080/gallery/v...02&id=DSCF0215

and an engine shot (its partially apart now and on the work bench):

http://reno.sytes.net:8080/gallery/v...02&id=DSCF0213

rscamaro73 · 12-22-2004, 11:50:00 PM

Not too shabby....except for the reverse gear. Ouch.

I'd (personally) painted the trans/bellhousing the opposite colors...(swap)....and the rods silver....but its not mine, so who am I to tell you what is right or wrong.

Motor looks nice too

Gary S · 12-23-2004, 10:14:00 AM

That reverse gear shows what happens if the clutch drags, and the driver keeps on driving the car for a while and letting it grind into reverse.

Hexx · 12-23-2004, 11:50:00 AM

The clutch is pretty worn out too forgot to mention this and we didn't take pics of it.

The pressure plate looks fine though, no scuffs or marks on it. I think the reason for the dead clutch is because he hammers on it

Basically ~400hp, big meats in the rear, and a tranny that is not easy to put into each gear (you have to be in the right rpm)....something else may be wrong but I dont know...Im not a tranny guy.

12-23-2004, 02:11:00 PM

I have found the only way to stop a Saginaw from doing that is to put it in first gear then in reverse. This will synch the gears up. Otherwise mine grinds like a bitch.

Camaroz · 12-23-2004, 05:56:00 PM

Ive actually had to double clutch to get into second before.

Steve

Hexx · 12-23-2004, 06:46:00 PM

Tried both lol

Joekool · 12-25-2004, 01:53:00 AM

FYI, no need to guess which gear is the reverse gear, most manual tranny's have reverse gear cut straight because no one cares about the noise a straight cut gear makes in reverse. Every manual tranny is a rock crusher in reverse.

ReD-DaWg-OnE · 12-30-2004, 05:34:00 PM

Quote:

<font face="Arial,Verdana" size="2">Originally posted by Gary S:
That reverse gear shows what happens if the clutch drags, and the driver keeps on driving the car for a while and letting it grind into reverse.</font>

Please explain... What do you mean when the clutch drags? I always put my tranny in 2nd before I shift into reverse. Also did the "rockcrusher" have all stright cut gears? Is there an advantage to doing it that way?

At Home Camaro · 12-31-2004, 12:29:00 AM

I believe that Gary meant when a clutch drags it does not fully release .... if it does not fully release and you shift into reverse, you are engaging (moving) one gear into another while one is being powered (by the dragging clutch) and the other is stationary (assuminig the car is not moving). Over time this tends to act like a lathe and will eat / chip / grind the gear teeth away.

Reverse gear is the only non-synchronized gear in a manual transmission. This means that you are actually sliding one gear into another. All other synchronized forward gears are always fully meshed. So as you slide that reverse spur gear into place and the very tips start to engage while the dragging clutch tries its best to keep things moving, the teeth simply grind themselves away.

I think that the rockcrusher did not have straight gears but had the teeth less angled than "normal". Straighter teeth are stronger and impart less side or thrust load on the shaft. However because the power transmission is not as smooth as an angled gear they tend to be noiser.