Notices
C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette

Is this normal for an auto box?

 
Old 05-16-2019, 02:59 AM
  #1  
Dusky
CF Senior Member
Thread Starter
 
Dusky's Avatar
 
Member Since: Nov 2017
Location: Belgium
Posts: 277
Received 8 Likes on 8 Posts
Default Is this normal for an auto box?

Hi guys!

I've been wondering a bit about my transmission :

When I'm cruising at 60 I'm doing 3500 rpm, when i let off the gas the revs almost instantly drop to 3.2K .
So it almost feels like my converter is still slipping 300 rpm.

When I'm cruising at 100 and I go full throttle it revs to 4K, like the converter is slipping again.

Is this normal? I've never driven auto's with this kind of power ( and this kind of freedom to play with them *laugh* )
Or what could the cause be? I do suspect the trans is overfilled atm (foaming => less 'pressure' in the converter causing it to slip?).

Specs:

Rebuilt th350 ( ALTO clutches, transgo street kit, 20-2.3K 10" stall converter JEGS 60402)
3.55 gears in the diff
No idea what hp the 350 engine makes - 0-100km/h is currently at 5.4s.

Last edited by Dusky; 05-16-2019 at 03:03 AM.
Dusky is offline  
Old 05-16-2019, 04:58 AM
  #2  
mrvette
CF Senior Member
 
mrvette's Avatar
 
Member Since: Jul 1999
Location: Orange Park Florida
Posts: 61,924
Received 131 Likes on 125 Posts
Default

Sounds like situation normal from what I read.....~300 rpm slip due to converter sounds normal to me.....

I have a 200 r4 trans in my '72, so lockup on the converter at speed, but a th350 does not have that option....
mrvette is offline  
Old 05-16-2019, 07:02 AM
  #3  
Dusky
CF Senior Member
Thread Starter
 
Dusky's Avatar
 
Member Since: Nov 2017
Location: Belgium
Posts: 277
Received 8 Likes on 8 Posts
Default



its overfilled right to first the L of FULL
You can see its foaming too. Best to remove some fluid?
Dusky is offline  
Old 05-16-2019, 08:28 AM
  #4  
Kacyc3
CF Senior Member
 
Kacyc3's Avatar
 
Member Since: Jun 2012
Location: Port St. Lucie Fl
Posts: 1,519
Received 93 Likes on 82 Posts
Default

Originally Posted by mrvette View Post
Sounds like situation normal from what I read.....~300 rpm slip due to converter sounds normal to me.....

I have a 200 r4 trans in my '72, so lockup on the converter at speed, but a th350 does not have that option....
there was a th350 with lock up, I believe it was called th350c

Originally Posted by Dusky View Post


its overfilled right to first the L of FULL
You can see its foaming too. Best to remove some fluid?

Are you checking the fluid with the engine running and warm after having been put in R,N,D,N,R,P for a few seconds each? Not doing so could give you a false reading.
Kacyc3 is offline  
Old 05-16-2019, 08:39 AM
  #5  
Dusky
CF Senior Member
Thread Starter
 
Dusky's Avatar
 
Member Since: Nov 2017
Location: Belgium
Posts: 277
Received 8 Likes on 8 Posts
Default

Originally Posted by Kacyc3 View Post
there was a th350 with lock up, I believe it was called th350c




Are you checking the fluid with the engine running and warm after having been put in R,N,D,N,R,P for a few seconds each? Not doing so could give you a false reading.
Yeah, idling in P
Dusky is offline  
Old 05-16-2019, 12:43 PM
  #6  
cuisinartvette
CF Senior Member
 
Member Since: Oct 2004
Location: Valencia Ca.
Posts: 68,799
Received 1,223 Likes on 1,120 Posts
St. Jude Donor '05
Default

SOunds like the nature of a converter with a slight stall. It wont engine brake like a stick would
cuisinartvette is offline  
 


Thread Tools
Search this Thread
Quick Reply: Is this normal for an auto box?


Sponsored Ads
Vendor Directory

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: