4l80e MVB issues
07-25-2014, 11:35 PM
#1
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4l80e MVB issues Hey guys,
Having some issues with my 4l80. With its application I will definitely get more help here then my normal boards. I have a MVB 4l80e via Jakes parts built by a local #1 and it was running great for over a year. Long story I ended up spinning a rod in my 2j and when I replaced the motor somehow had front pump seal issues immediately and lead to a front pump failure via wear. I believe it was an issue with the adapter plate. I replaced the pump but think it was too late as the trans had slipped before due to line pressure being down (presumed) and lead to a failure shortly afterwards.
Fast forward to now,
Trans builder #1 is no longer living in MD so it just came back from Trans builder #2. I ended up toasting the 36 element drum and all the clutches/steels so he put a 34 element in. His diagnoses was a failed ECS relay.
Installed the trans and took it for a 10 mile drive to the local ihop for breakfast. Shifted fine on the way there (didnt pay attention to 2-3 or 3-4 shift as just locked up converter and cruised). When I left 1-2 shift barks tires like normal (fixed line pressure), then from second gear, 3 and 4th gear are "not shifting" trans just stayed in second gear NOT neutral. I just limped it home in second doing 30mph in the shoulder.
When it cooled down and went to take the builder for a ride. First gear is great, bangs second great, then 2-3 shift was PATHETIC but was existant and same with 3-4 shift. Drove it around about 10 miles again and was still working. Let it sit and once again, lost 3rd and 4th but STAYS in second no matter what manual gear selector is in.
Has a Jakes box powering the solenoids and they are getting 12 volts KO. Builder is saying possibly the boost valve in the pump but it does not make any sense to me.
I am no trans guy but my gut is saying its a line pressure or VB issue. Any insight or thoughts would be great. I will be pulling the trans tomorrow as he had mentioned the previous builder used a torrington bearing on the front hub as its a th400 component it needed a bushing, but Jakes IS machined for a torrington so he will have to take it back apart to switch atleast this back out. I just want to know if there is something else I need to tell him to check.
THANK YOU as I know this post is long winded
Having some issues with my 4l80. With its application I will definitely get more help here then my normal boards. I have a MVB 4l80e via Jakes parts built by a local #1 and it was running great for over a year. Long story I ended up spinning a rod in my 2j and when I replaced the motor somehow had front pump seal issues immediately and lead to a front pump failure via wear. I believe it was an issue with the adapter plate. I replaced the pump but think it was too late as the trans had slipped before due to line pressure being down (presumed) and lead to a failure shortly afterwards.
Fast forward to now,
Trans builder #1 is no longer living in MD so it just came back from Trans builder #2. I ended up toasting the 36 element drum and all the clutches/steels so he put a 34 element in. His diagnoses was a failed ECS relay.
Installed the trans and took it for a 10 mile drive to the local ihop for breakfast. Shifted fine on the way there (didnt pay attention to 2-3 or 3-4 shift as just locked up converter and cruised). When I left 1-2 shift barks tires like normal (fixed line pressure), then from second gear, 3 and 4th gear are "not shifting" trans just stayed in second gear NOT neutral. I just limped it home in second doing 30mph in the shoulder.
When it cooled down and went to take the builder for a ride. First gear is great, bangs second great, then 2-3 shift was PATHETIC but was existant and same with 3-4 shift. Drove it around about 10 miles again and was still working. Let it sit and once again, lost 3rd and 4th but STAYS in second no matter what manual gear selector is in.
Has a Jakes box powering the solenoids and they are getting 12 volts KO. Builder is saying possibly the boost valve in the pump but it does not make any sense to me.
I am no trans guy but my gut is saying its a line pressure or VB issue. Any insight or thoughts would be great. I will be pulling the trans tomorrow as he had mentioned the previous builder used a torrington bearing on the front hub as its a th400 component it needed a bushing, but Jakes IS machined for a torrington so he will have to take it back apart to switch atleast this back out. I just want to know if there is something else I need to tell him to check.
THANK YOU as I know this post is long winded
07-25-2014, 11:58 PM
#2
Weak shifts indicate low pressure. The builder probably missed something during the build.
We dyno test the transmissions before they ship but we still encourage the installer to use a pressure gauge because it is very helpful to diagnose installation issues such as fluid level and tuning.
I think a pressure gauge would be helpful in your current situation.
We dyno test the transmissions before they ship but we still encourage the installer to use a pressure gauge because it is very helpful to diagnose installation issues such as fluid level and tuning.
I think a pressure gauge would be helpful in your current situation.
