Author Topic: Neutral and engine rpm  (Read 1124 times)

Offline mojavered

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Neutral and engine rpm
« on: December 21, 2016 - 10:03:52 PM »
I recently had my 727 rebuilt.  Finally had some time to put it in (hope I never have to do it again!) Started in neutral on stands and went through gears and made sure all was working properly!  Took it around a few blocks to get it all warmed up for checking fluid level and went to park it.  I notice that the rpm's do not change from 1,2,3,n, or reverse, but do change in park.  Trans is a manual valve body (old trans did not have).  Anything to look for?  Concerned about checking the fluid level in neutral.  When selector is in neutral, car does not roll.  It does have wheel spin if off the ground.  I shut it down and called it quits for the night.  Thanks for the help!
Jason




Offline Beekeeper

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Re: Neutral and engine rpm
« Reply #1 on: December 21, 2016 - 10:18:29 PM »
when you say the rpm's do not change in the different gears, are you saying that when its at dead stop, you can shift it from neutral or park into 1,2, or 3 and all three drop the rpms by the same amount?

As I understand these trans, you should be able to shift into first (all the way down) and the rpm's should drop a bit as the trans initially engages just like a regular auto trans. This would happen with any auto trans when shifted from neutral or park into a gear (any gear). It's not under load so the rpm's are higher. Once in a gear (any gear), it's under load and will drop a bit. It should drop the same amount if you dropped it into 2 from a dead stop instead of 1. Of course, you would then be starting off in 2 when you should start in 1 and work your way up.

I hope I understood your question okay.

Offline jhaag

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Re: Neutral and engine rpm
« Reply #2 on: December 22, 2016 - 12:44:30 AM »
I think you are asking why the idle speed does not go up in neutral as it does in park? First I would not worry about the wheels spinning when they are off the ground in neutral, that is not uncommon. Because you have a manual valve body the fluid is routed differently and most likely is why you are experiencing what you described. If all worked well on the test drive, I would not be concerned. For peace of mind talk to the trans builder, or valve body manufacturer.  :2cents:
love 70 Challengers

Offline mojavered

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Re: Neutral and engine rpm
« Reply #3 on: December 22, 2016 - 12:04:33 PM »
Correct, idle speed is what I was referring to.  Idle speed does not change from gear to neutral and visaversa. I will check with shop.  Thanks.
Jason

Offline 6packCuda

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Re: Neutral and engine rpm
« Reply #4 on: December 23, 2016 - 09:44:17 PM »
I think you are asking why the idle speed does not go up in neutral as it does in park? First I would not worry about the wheels spinning when they are off the ground in neutral, that is not uncommon. Because you have a manual valve body the fluid is routed differently and most likely is why you are experiencing what you described. If all worked well on the test drive, I would not be concerned. For peace of mind talk to the trans builder, or valve body manufacturer.  :2cents:

 :iagree:
Dave

Offline chargerdon

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Re: Neutral and engine rpm
« Reply #5 on: January 22, 2017 - 11:44:40 AM »
There will be a slight drop in idle speed when putting the transmission into any gear including neutral because of the load from the transmission.   Park and Neutral are different.  On our torqueflites you check the fluid in neutral not park, because when in park the pump is not running whereas in neutral the pump is functioning.   Also accounts for the small drop in idle speed when in neutral vs park.   Ie..pump running in neutral but not in park.