Pirate 4x4 banner

1 - 6 of 6 Posts

·
Registered
Joined
·
323 Posts
Discussion Starter #1
So I recently pulled a th400/205 combo that had a leaky adapter setup out of my truck because I came across a 86 K30 3+3 Dually(parts truck) that had a 400/205 as well. The old combo was working fine until about a week before I pulled it out. It developed no engine braking in second gear. Same issue manually shifting. Rpm's would drop to idle off the throttle, and rev up until catching up with speed. I checked the fluid and it was full and normal.
When it came time to remove the trans, I noticed the vacuum line to the modulator was loose and cracked. Before I put the other trans in I put a B/M #20228 Trans pack kick in and a stock GM deep pan. I put a few quarts through it to flush it and a large cooler went up front. When it came time in install I put a new section of vacuum hose to the hard line behind the trans/engine. I also changed the rubber section on the upper portion of the intake. When it came time to drive the truck. Same issue.
Vacuum issue?
Modulator?
Second gear sprag or band?
 

·
Registered
Joined
·
323 Posts
Discussion Starter #2
Different tranny. I had a 400 to A.A. unit to sm465 adpater and 205case. It had that problem, and leaked bad.
I got another other combo out of a parts truck that drove fine...
 

·
Registered
Joined
·
4,465 Posts
Where are you drawing your vacum for the modulator from? Check the whole line and see if it melted cinked or blocked. You can also adjust your shift points within the center of the modulator(small flathead screwdriver)
 

·
Registered
Joined
·
12,234 Posts
The direct clutch was out on mine when it did this - ( on my dually ) the apply piston was fractured , you need to have it backdated the newer ones use tephlon and older use cast iron rings -the older is much better -Jess
 
1 - 6 of 6 Posts
Top