47re 2nd gear downshift
 

Hello all,

I just had my transmission rebuilt and am curious about manual downshifting to second gear. Before it was rebuilt I could manually downshift to second gear (to use the motor to slow me down) and it would downshift if I was under 40 mph. Now that it has been rebuilt I have to be under 30 or slower. Is that normal? At what speed should I be able to downshift to second at? Is there something that is out of adjustment or is it just because everything is still new and not broke in?

The transmission was rebuilt locally here and has a Revmax Tow VB and a DPC triple disk in it.

Any help would be much appreciated.

I suspect it has something to do with the VB setup, but I could be wrong. What does it do if you manually downshift to accelerate?

When I am going less than 25mph (double checked that last night) it will down shift fine. Also when I put it in second gear and start from a stop it shifts up to second then stops. It seems like everything works like it normally should except for the speeds that it will manually downshift at.

Thanks

That isn't exactly what I asked. And by design, these transmission don't like to be manually downshifted to slow down. It causes binding inside, which may be why yours isn't doing it when you want it to. If you want to be in second gear for engine breaking, you should already be in second gear when you start slowing down.

Hello,

Sorry for the late reply. I was out of town with no internet.

Anyways, I must have misunderstood your prior question of manually downshifting to accelerate. Are you saying put it in 2nd then accelerate from a stop or while rolling or something else?

The issue is getting it into second gear to slow down. I will be coasting at the crest of a hill say at 35 mph and just before I begin to go down the hill I want to downshift (no load and no throttle) so I can slow down.

I appreciate the help.

I meant rolling. You're cruising along 30mph or so in drive, need to get up and go and pull it down into 2nd and punch it. What happens?
Also, you aren't supposed to do this to slow down. There should be at least a little bit of load on it when you downshift.

If I am below 25mph which is the speed it will downshift at it will downshift then stay in second. If I am above 25 it will stay in third and not shift into OD.

So if I'm not supposed to downshift to slow down how am I supposed to engine brake? Stay in 3rd and get a lock up switch? Sorry if that's a really dumb question...

Thanks again

Not a dumb question, that's exactly how. The user's manual actually does say to use the first two gears if you want low speed engine braking, but they don't clarify that the intent here is that you're taking off in the the gear you are going to stay in, not slowing down to a speed that gear would be appropriate in. Granted, it isn't nearly as bad for the transmission as manually downshifting to slow down in lockup is, but it still causes a binding situation. And depending on how your trans was rebuilt, it seems logical to me that it might be too tight to allow it to do what you're telling it to when you downshift to slow down. I don't know that that's the case, it's just an idea. But generally, if you want engine braking, the lockup switch is the way to go.