just tossing aroud the idea of rebuilding the tranny while we have it out....
First...where does a 904 main come from
and what gears should be used with a stock 3.0
LSD..opinions
steve

could a 904 mainshaft come from a 904

there were replica shafts, so you can get rare 2nd gear sets to change out....

play with a gearing chart

any suggestions on gear sets and where to get them?
are there any tranny guys around.....hmmm "tranny guys" sorry i meant transmission guys

Stock 914 gears are fine unless you want to drive more agressively....
LSD is needed if you really want to plant the HP down and have bigger tires. For fun driving its not needed.
Otto's sells the 904 mainshafts
Gears can be had in alot of places, Gary Emory still has a bunch I hear

Unless you're racing and need to be changing 2nd gear ratios for different tracks and stuff, you don't really NEED a 904 mainshaft. Most of the 2nd gear ratios you'd probably want are available on more common mainshafts. Just make sure the manshaft you buy comes with the other part of second gear that fits on the pinion shaft.

i am not sure how to get a hold of these guys...like Otto and Gary Emory

Go to partsobsolete.com and you will find a phone number for Gary Emory. I think he is closing out the parts business. I know he had some great prices on bumpers, doors, hoods, etc last summer. Maybe a good deal could be had on gears as well.

I welded an "I" gear onto my mainshaft after cutting the "F" gear off. Probably a whole lot cheaper than a 904 mainshaft if you don't need to keep changing second gear ratios.

I've been doin' some shopping lately.
Last I talked to Emory, he said he had lots of gears.....but he also said(paraphrase)...."you'll have to go look for em'."....waving vaguely at the back 40.

Otto is out of 904 main shafts, but has lotso gears. Better to call than email. He has a website.

As to what gears.....what is your usage?
1st is so low as to be usless.....it's good for about 60 feet for me.38 mph ..... my calculations IIRC. 45mph would be better.
2nd is good to 58 mph (both at 7100 rpms) 65 would be better. I AX and most courses are set up for about 60 mph tops for a fast car & I'm tired of bouncing off the limiter.

IMO, on the street, save your money for something else & use the stock ratios.

Diffs? I have a line on something. I'll have to get back to ya on that. (that means I gotta get one first)

QUOTE (Racer Chris @ Nov 17 2005, 04:15 PM)

I welded an "I" gear onto my mainshaft after cutting the "F" gear off. Probably a whole lot cheaper than a 904 mainshaft if you don't need to keep changing second gear ratios.

How did you do that? I tried to do some machining on the shafts in an early experiment of doing something similar. Carbide bits would just scratch them.

QUOTE (bondo @ Nov 17 2005, 04:48 PM)

QUOTE (Racer Chris @ Nov 17 2005, 04:15 PM) I welded an "I" gear onto my mainshaft after cutting the "F" gear off.  Probably a whole lot cheaper than a 904 mainshaft if you don't need to keep changing second gear ratios. How did you do that? I tried to do some machining on the shafts in an early experiment of doing something similar. Carbide bits would just scratch them.

nice idea chris! ive heard of it being done before....

what are your new ratios?

1 - A AA B or C?
2 - I
3??
4??
5??

too cool trans stuff fascinates me

QUOTE (bondo @ Nov 17 2005, 06:48 PM)

How did you do that? I tried to do some machining on the shafts in an early experiment of doing something similar. Carbide bits would just scratch them.

The teeth are hard but the underlying shaft metal isn't. I used an abrasive belt to remove the teeth of the stock gear, then handed it off to my favorite machinist who turned it down so the new gear would just slip on with light pressure. They didn't mention having any difficulty at all.
For added security I built up splines with a TIG welder that aligned with the slots in the new gear, then I carefully welded the new gear in place, taking my time to avoid overheating the shaft and gear. I didn't do a full perimeter weld but I did stitch welds on both sides of the gear. The welds were not that large but I was careful to get good penetration and make the beads convex (ie. extra filler wire) for crack resistance.
Now I wish I had taken pictures.

QUOTE (Aaron Cox @ Nov 17 2005, 06:56 PM)

what are your new ratios?

A,I,M,Q,V
for an engine with 8000+ redline and about 180hp.

QUOTE (Racer Chris @ Nov 17 2005, 05:00 PM)

QUOTE (Aaron Cox @ Nov 17 2005, 06:56 PM) what are your new ratios? A,I,M,Q,V for an engine with 8000+ redline and about 180hp.

stock r/p?

wow. v for 5th pretty short.
whats 8000rpm with your tires in 5th? little over 95? 100?

QUOTE (Racer Chris @ Nov 17 2005, 04:57 PM)

Now I wish I had taken pictures.

Me too!

Sanding off the teeth... brilliant!

On pelican some where there is a thread with a "How to change 901 second gear" by machining and welding. By Grady Clay I think.
Old School get er done

QUOTE (sixnotfour @ Nov 17 2005, 07:41 PM)

On pelican some where there is a thread with a "How to change 901 second gear" by machining and welding. By Grady Clay I think. Old School get er done

He posted a reply to my inquiry earlier this year on the AX and racing forum over there. I didn't follow his directions exactly, but made up my own procedure using his info as a starting point.

QUOTE

wow. v for 5th pretty short. whats 8000rpm with your tires in 5th? little over 95? 100?

Try 133 mph!
I don't think I've been above 120 yet.

Ok if i am not going to use a 904 main what are my gear options for a driver with a stock 3.0 and 16inch wheels with 40 series tires...

For 1st: AA, B or C. B is about unobtanium. Ask AAron C will run you 3-400
from Otto...more from power House. A 'B' cost me 400

for 2nd: GA. stock 914/6 mainshaft....they can be found, but it may take some time. I got one relatively cheep.

Thas all I know. I have no problem with the rest of the gear ratios. With more torque than I, you shouldn't either.....IMO

BTW, I popped for a Guard TB diff bout an hour ago. 1200.

QUOTE (J P Stein @ Nov 17 2005, 07:12 PM)

For 1st: AA, B or C. B is about unobtanium. Ask AAron C will run you 3-400 from Otto...more from power House. A 'B' cost me 400 for 2nd: GA. stock 914/6 mainshaft....they can be found, but it may take some time. I got one relatively cheep. Thas all I know. I have no problem with the rest of the gear ratios. With more torque than I, you shouldn't either.....IMO BTW, I popped for a Guard TB diff bout an hour ago. 1200.

yup. id say stock 1st = A (for price)
GA main = 300 bucks or so
then stock gearing with a ZD fifth (taller = better cruising)