Alum vs Steel Drum
 

Need your help! Do you think there is alot of Et or MPH change with a steel or alum drum(5 Clutch pack) in a 2 speed? SS/ 275hp 327chev. We killed a new Ati alum in one pass! Thanks, Ron

Re: Alum vs Steel Drum
 

An aluminum high gear drum makes a measurable difference in a Powerglide, especially in a small block car. If you hurt a new ATI part, call them, they'll make it right if it is their fault.

Re: Alum vs Steel Drum
 

Thanks Alan, I will call them and see what they say. Just haven't had luck with warr parts. It was the new one with the steel insert. May have to put the old Ati back in for the next race.

Re: Alum vs Steel Drum
 

I found no difference when I went from the aluminum drum to the steel drum. I used the Coan lightened steel drum in one trans. That worked real good. I have a stock one in the trans I have I the car now. What happened to the drum that just tore up?

Re: Alum vs Steel Drum
 

It was torn up bad, like the band wasn't releasing in high. All we did is replace it with a new band and steel drum and cleaned the trans and it was great. ATI won't call back after a few messages left.

Re: Alum vs Steel Drum
 

What band did you use with the aluminum drum? What was the band adjustment procedure?

Re: Alum vs Steel Drum
 

My trans guy did that but I thought it was 3 and 3/4 out, and the red band.

Re: Alum vs Steel Drum
 

I always used a red band and ran the band at 3 1/2 turns from snug. I had some problems with a front pump that was not giving me enough pressure and was eating bands and drums. You need at least 170 lbs of pressure according to Coan. I use a Kevlar band on the steel drums. I would only use an aluminum drum if you are trying to get that last .001 or .002 to set a record or a class run situation. The steel drum does not leave the gray mess in the pan either. The lightened steel drum from Coan is a good alternative.

Re: Alum vs Steel Drum
 

Any idea how much? Does he keep them on hand?

Re: Alum vs Steel Drum
 

I have used both and the aluminum drums don't hold up especially in higher rpm applications. On the other hand the lightweight steel drum from Coan worked great...the problem is they no longer make it. I called 2 weeks ago because I couldn't find it on their website anymore and was told they couldn't get enough steel drums to make them but if you have 10 drums you could send them in and they might would machine them. So there is an option to get them made.