I am doing my first rebuild this weekend (1987 700r4) and the kit that i bought came with everything but a new set of steels. Do you I need these to rebuild correctly? The tranny has over 100k on it.

 

Yes replace the steels also,and where did you get the kit from

 

The majority of the time, steels are fine. If they look burnt or a straight edge shows them warped, they should be replaced. Measure them to see if they're still above minimum spec.

I reuse the steels in my powerglide with no problems. I did purchase some thinner ones to get more clutches into the pack.

 

If the steels look ok, no leopard spots or the metal looks like it has "smeared", and they are flat, you could polish them with 600 or finer sandpaper in direction of rotation. The more of a "mirror" finish, the better. Make sure that there are no nicks (remove them) in the steel clutch, which will groove the clutch material. What type of clutch material are you using in the 3-4 clutch pack?

 

As above if not warped, spotted or burned I'd ruff em up with a stone , Emory cloth or sand paper and reuse em. I did that to mine but was instructed to go for a cross hatch Pattern as opposed to the "mirror" finish suggested above. I also laid a straight edge across the drum in several spots, deemed it serviceable and hit it with the abrasive too.

Your call. If your budget and timetable will allow new it couldn't hurt.

 

I've re-used steels for two th400 builds. I ALWAYS set the clutch pack height within specs, as should all trans builders.