Cummins Diesel Forum banner
Cancel

48re slipping going into 4th gear

527 Views 7 Replies 2 Participants Last post by  rghavana, 
Cumminsboy2332
I have a 04.5 24v with a firepunk 48re towmaster that I have rebuilt due to a stock input shaft failure, I followed instructions from the ATSG book and firepunk themselves on the rebuild. The valve body has a transgo shift kit included, I have set my line pressure on the valvebody to 33.4mm as the ATSG called for, and my throttle pressure screw to .820 as I seen on a sonnax post.
Gas Font Engineering Machine Security

Mine is equipped with a tv cable so I went with the cable activated measurements. My 1st-2nd shift is decent after adjusting front bands(72in pounds and backed off two full turns). Then when I get to 3rd it’ll slip going into 3rd, so I have to let off and it’ll make a little clunk then go in gear, then I easily have to get it to go without slipping. once I get to 40mph it’ll slip and not go any faster to get to OD. I’m new to this, any sort of information on this would be a greatly appreciated.
See less See more
Reply
Save
Like
1 - 8 of 8 Posts
rghavana
If you installed shift kit need to check what pressures are, make sure they match what ever your build was designed for.
Reply
Save
Like
Cumminsboy2332
rghavana said:
If you installed shift kit need to check what pressures are, make sure they match what ever your build was designed for.
Click to expand...
I’ve ordered a trans line pressure gauge kit, firepunk called for 180psi in 3rd locked. I was wondering if anyone might know how many turns I should taking compressing the spring on the line pressure valve
Reply
Save
Like
rghavana
IMO, that would really depend on which transgo shift kit you have and wear and tear of parts .
should have a ball park number with instructions. Have you tried to contact Transgo?
Reply
Save
Like
Cumminsboy2332
rghavana said:
IMO, that would really depend on which transgo shift kit you have and wear and tear of parts .
should have a ball park number with instructions. Have you tried to contact Transgo?
Click to expand...
I’ve contacted firepunk diesel and all I got from them is 3rd gear locked at WOT I should have 180psi. And and driving it I can’t even go WOT in 3rd without it slipping and I only have like 140psi before it slips. Also when the fluid is cold the trans shifts nice and goes through all gears nicely but when it warms up it’ll slip the 3rd-4th shift and won’t shift into 3rd unless I let off but both of those go away when it’s cold.
Reply
Save
Like
rghavana
Should be pressure testing/checking fluid level at operating temp, ATF fluid viscosity is going to change according to temp which effects pressure.
At a minimum should have line pressure @ idle psi number, line pressure WOT psi number and reverse/front clutch psi numbers.
That is controlled by valve body, I would be contacting Transgo or search on thier website for that info.
There are different versions of Transgo kits, they should be able to give you an idea of what thier parts do to alter pressures. ie how many turns to lower or increase, what springs etc.
Reply
Save
Like
Cumminsboy2332
rghavana said:
Should be pressure testing/checking fluid level at operating temp, ATF fluid viscosity is going to change according to temp which effects pressure.
At a minimum should have line pressure @ idle psi number, line pressure WOT psi number and reverse/front clutch psi numbers.
That is controlled by valve body, I would be contacting Transgo or search on thier website for that info.
There are different versions of Transgo kits, they should be able to give you an idea of what thier parts do to alter pressures. ie how many turns to lower or increase, what springs etc.
Click to expand...
Font Parallel Design Circle Engineering

transgo recommends putting the adjustment plate on the line pressure flush with the bracket which I’ve already tried that and it didn’t have pressure for **** it had even thrown a low line pressure code 😂. And I’ve heard from some people also say the same that it just isn’t enough pressure
See less See more
Reply
Save
Like
rghavana
That is the kit you have, from 2009?
that is a starting point, might need to adjust pressure.
if your adjusting it and no increase then need to figure out why,

Did you "Install Spring Seat as shown. Make sure flat on spring
seat has some clearance from casting. File casting if
necessary to give it a little room to rotate slightly. Do
not allow it to bind between PR valve and casting!
Recheck this just before installing VB into case."

good info here on checking/adjusting psi
Fine Tuning Your Dodge Automatic 47re/rh Series (46 and early 48 series similar) - Transmission & Transfer Case - Mopar1973Man.Com LLC
Reply
Save
Like
1 - 8 of 8 Posts
Cummins Diesel Forum
A forum community dedicated to all things Cummins Diesel! Originally founded for owners and enthusiasts of Cummins powered Dodge pickups, the Cummins Forum has expanded to include ALL Cummins Engine applications! Come join the discussion about reviews, drivetrain swaps, turbos, modifications, classifieds, builds, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
03-07 Performance Parts Discussion 03-07 Powertrain 2013-2018 General Discussion 98.5-02 Powertrain 98.5-02 Performance Parts Discussion
Top