When to replace transmission bands?

[MericaMopar]

I have a newbie trans rebuild question…how do tell if you need to replace the two bands in an unknown condition 727?

Some backstory, i acquired a transmission that has been sitting for a bit and i am going through it doing a refresh with new seals and clutches. It is supposed to be a good unit but it definitely had some leaks and the bearing on the rear shaft has some grit/dirt in it from sitting with no slip yoke in the trans.

The friction material on the bands look fine. Do you guys replace the bands because you’re in there? Just leave them alone if they look fine? Is there a thickness spec for them?

Thanks

 

[david hill]

While examining the low reverse band if there are no scuff or abrasions on the band material. See if you can pick or lift off any band material w/ you fingernail. if it passes all of the above, it's usable. Always replace the kick down band. Cheap insurance.

 

[CBODY67]

IF you do decide to install new frictions, make sure they are of at least OEM quality, in a known quality brand name. There are lots of aftermarket rebuild items/kits available. They will work decently well, for a while or longer. I've always been one to "buy the brand name" unless something else had been reliably-shown to be just as good at a lesser price or similar. There are also some "rebuilder brands that are good, too.

CBODY67

 

[MericaMopar]

IF you do decide to install new frictions, make sure they are of at least OEM quality, in a known quality brand name. There are lots of aftermarket rebuild items/kits available. They will work decently well, for a while or longer. I've always been one to "buy the brand name" unless something else had been reliably-shown to be just as good at a lesser price or similar. There are also some "rebuilder brands that are good, too.

CBODY67

I am going with A&A transmission's parts, red frictions with kolene steels rebuild kit and his thrust washer kit as the rebuild kit doesn’t look like it comes with thrust washers or plastic spacers.

 

[MAXWEDGECHAR]

I would use a new one regardless. Once you're in everything gets replaced.

 

[MONC440]

Just my opinion but I always replace both bands. If they are the originals then they are 50 years old. Sounds like you are using good parts I use the exact same ones in most of my rebuilds. The low/reverse band doesn’t get as much wear as the forward band but they tend to break more often from people hitting reverse to hard usually from getting stuck and shifting back and forth between forward and reverse when stuck in mud or snow. You are already rebuilding so why not spend an extra $40 for your peace of mind.