Downshifting TH400
04-12-2005, 07:52 PM
#21
Last question, I swear 
So how does the manual/auto work? When you leave it on Drive, it drives on its own, and then if you want to do it manualy you just put the gear selector back for 3rd, then back again for 2nd, and back once more for 1st? Does it feel similarly to the 4L60e when you try to drive it like a manual?
So how does the manual/auto work? When you leave it on Drive, it drives on its own, and then if you want to do it manualy you just put the gear selector back for 3rd, then back again for 2nd, and back once more for 1st? Does it feel similarly to the 4L60e when you try to drive it like a manual?
Originally Posted by jxaxsxoxn
This is also what might happen if you don't drive a rmvb th400 properly.
I have one in a nova behind a 438 big block. I can go say 110 and put it in first and it'll idle.
Now why is that not good? First off doing this with no front band over runs the direct drum, thats why the one in the picture isn't there, the drum is gone.
Another thing that happens is the drum over runs so fast it slings oil out of the intermediate sprag and this can burn it up due to lack of lube. I've seen that happen once.
You can downshift for those ricer fly bys.
I was going 40 mph once and a girlfriend of mine was in a saturn coming up on me going 80. About a car length away I dropped down from third to first just to pop the rpm up to around 7500, then I hit second and third. She never passed me.
If you drive like this you must really know your car well. I have no rev limiter, that just means you have to know what your rpm is going to do. Sometimes I hit first only for a split second then pull down to second gear.
If I had worse traction doing this could be a real problem.
I have one in a nova behind a 438 big block. I can go say 110 and put it in first and it'll idle.
Now why is that not good? First off doing this with no front band over runs the direct drum, thats why the one in the picture isn't there, the drum is gone.
Another thing that happens is the drum over runs so fast it slings oil out of the intermediate sprag and this can burn it up due to lack of lube. I've seen that happen once.
You can downshift for those ricer fly bys.
I was going 40 mph once and a girlfriend of mine was in a saturn coming up on me going 80. About a car length away I dropped down from third to first just to pop the rpm up to around 7500, then I hit second and third. She never passed me.
If you drive like this you must really know your car well. I have no rev limiter, that just means you have to know what your rpm is going to do. Sometimes I hit first only for a split second then pull down to second gear.
If I had worse traction doing this could be a real problem.
04-12-2005, 08:42 PM
#22
JimmyP.
With a full manual valve body it will start out in what ever gear the shifter is set at, you can start out from 0 mph in third, second. You can also downshift at any speed.
With a trans that has the average shift kit in it, it will start out in first gear no matter what, you can start out with the shifter in first and hold it there until your engine blows up. It'll never upshift automatically.
If you start out in with the shifter in third at 0 mph the trans will start in first, automatically shift to second and then third.
You could also downshift at any speed even if it's so fast it blows your engine up.
With a stock trans it usually will start out in first no matter what forward gear the shifter is in.
But it has safety features built into it to prevent over revving. Most will automatically upshift into second (when the rpm gets too high) even with the shifter in first.
And most will pervent you from down shifting into first at high mph. If you put the shifter in first at a high speed it might downshift into second but it won't go into first until the mph is low. This is not the best in high performance vehicles where you want more control.
With a full manual valve body it will start out in what ever gear the shifter is set at, you can start out from 0 mph in third, second. You can also downshift at any speed.
With a trans that has the average shift kit in it, it will start out in first gear no matter what, you can start out with the shifter in first and hold it there until your engine blows up. It'll never upshift automatically.
If you start out in with the shifter in third at 0 mph the trans will start in first, automatically shift to second and then third.
You could also downshift at any speed even if it's so fast it blows your engine up.
With a stock trans it usually will start out in first no matter what forward gear the shifter is in.
But it has safety features built into it to prevent over revving. Most will automatically upshift into second (when the rpm gets too high) even with the shifter in first.
And most will pervent you from down shifting into first at high mph. If you put the shifter in first at a high speed it might downshift into second but it won't go into first until the mph is low. This is not the best in high performance vehicles where you want more control.
04-14-2005, 07:37 PM
#23
My buddy that is doing my swap for me is telling me the reverse manual is much better and more fun than the frontal manual.He just put one in his 4th generation Trans Am,and he says he downshifts all the time. Is the wear on the trans gradual, or will it come all at once from downshifting? From what I have read, there are people that still downshift with the reverse manuals without a problem..Making choices like this is hard.
04-14-2005, 08:05 PM
#24
explode
Originally Posted by jxaxsxoxn
This is also what might happen if you don't drive a rmvb th400 properly.
I have one in a nova behind a 438 big block. I can go say 110 and put it in first and it'll idle.
Now why is that not good? First off doing this with no front band over runs the direct drum, thats why the one in the picture isn't there, the drum is gone.
Another thing that happens is the drum over runs so fast it slings oil out of the intermediate sprag and this can burn it up due to lack of lube. I've seen that happen once.
You can downshift for those ricer fly bys.
I was going 40 mph once and a girlfriend of mine was in a saturn coming up on me going 80. About a car length away I dropped down from third to first just to pop the rpm up to around 7500, then I hit second and third. She never passed me.
If you drive like this you must really know your car well. I have no rev limiter, that just means you have to know what your rpm is going to do. Sometimes I hit first only for a split second then pull down to second gear.
If I had worse traction doing this could be a real problem.
I have one in a nova behind a 438 big block. I can go say 110 and put it in first and it'll idle.
Now why is that not good? First off doing this with no front band over runs the direct drum, thats why the one in the picture isn't there, the drum is gone.
Another thing that happens is the drum over runs so fast it slings oil out of the intermediate sprag and this can burn it up due to lack of lube. I've seen that happen once.
You can downshift for those ricer fly bys.
I was going 40 mph once and a girlfriend of mine was in a saturn coming up on me going 80. About a car length away I dropped down from third to first just to pop the rpm up to around 7500, then I hit second and third. She never passed me.
If you drive like this you must really know your car well. I have no rev limiter, that just means you have to know what your rpm is going to do. Sometimes I hit first only for a split second then pull down to second gear.
If I had worse traction doing this could be a real problem.
Last edited by john kilgore; 04-14-2005 at 08:07 PM. Reason: not complete
04-14-2005, 10:05 PM
#25
TECH Fanatic
iTrader: (1)
Join Date: Jun 2002
Location: Houston,Tx
Posts: 1,844
Likes: 0
Received 0 Likes
on
0 Posts
i dont under stand either. i am trying to figure it out also. we have a th350 in my buddies car with a rmvb and you can be going 60 in third and down shift to first and it will just roll like you pushed a clutch in on a manual. but then when you hit the gas the rpm's will raise to acommidate the speed and being in first gear. i am going to call the builder and talk to them. i am gona put an 80 in my truck and would like to be able to manualy down shift it and it not slow the truck down.
04-14-2005, 10:19 PM
#26
ive never had an issue with my th400 rmvb, and i down shift all the time on the street. i never go into 1st at 80 but then again if im doing 40 and im in 3rd i have no prob downshifting into 2nd while my foot is burried in the gas. i think what everyone is saying is you have the potential to break the trans if youre doin 90 and try to shift into 1st. i also had no rev limiter (basically) and i know my car very well. you do have to watch it a few times and determine where 1st ends and 2nd ends etc. and also i did all this with no speedo. goin off rpm and buttometer for speed. never had an issue, over 2 years now, 4400 stall, transbrake.
04-18-2005, 12:55 AM
#33
TECH Addict
iTrader: (36)
Join Date: Apr 2002
Location: Murphy, Tx
Posts: 2,526
Likes: 0
Received 0 Likes
on
0 Posts
I use to drive mine around all the time. I drove it for over a year no problems downshifter on the hwy or anything. It was a full rmvb. with a 3500 tight stall. sucked on the hwy though. It was my dd so I used it everyday drove 30 miles plus to work. and more when there are gtg. when i would down shift at 100+ it would just idle. Sold the car though, so I no longer have it.
04-18-2005, 01:36 AM
#34
with a rmvb TH400 with no forward band you do not want to rev it it up high in 2nd and let off of it.
Most likely nothing will happen but it CAN happen, especially if someone lightened up the direct drum which used to be pretty common. Some valve bodies have a 'safety nuetral' in 2nd gear and you can put it in 2nd after a pass and the car just coasts, easier on an aluminum rodded motor coming down from 8000rpm
Its always a good idea to know whos valve body you have in the car and dont be afraid to call the company and ask them if its OK to downshift and nail it or coast.
Most likely nothing will happen but it CAN happen, especially if someone lightened up the direct drum which used to be pretty common. Some valve bodies have a 'safety nuetral' in 2nd gear and you can put it in 2nd after a pass and the car just coasts, easier on an aluminum rodded motor coming down from 8000rpm
Its always a good idea to know whos valve body you have in the car and dont be afraid to call the company and ask them if its OK to downshift and nail it or coast.
