RoughER shifting after an transmission oil change?

[sargentwolf]

So drained my '98 M1078 of engine and tranny fluid. Refilled everything, its running smoother now, in fact, the gauge gave me one heck of a scare when slowing down today during the shake down run....started dropping FAST (didnt notice it before.... 40psi is safe @ idle, right?)

Problem is the transmission. I did refill it with oil, fresh filters (x2), greased everything down there as well (lots of dry zerks!) Issue is it was REALLY jerky when upshifting. To the point that stuff in the cab slid when it jumped gears.

Should I be worried or is that just the truck being happy for new fluids?

Oh and dont ever EVER trust filter hour/date changed markings....freaking carl didnt do a single filter he says he did.

 

[Lmtv772]

The fresh oil probably caused the harder shifts due to higher viscosity. I and overdrive have changed to transmission fluid. Overdrive blazed the trail and wrote a thread about it.
http://www.steelsoldiers.com/showth...ssion-Fluid-Change-To-ATF-Write-Up&highlight=
Update: I had a email bulletin sent to me the other day. The Unit motor pools are to not use engine oil in the transmissions anymore

40lbs at idle is normal 60lbs under load .

 

[Overdrive]

Thumbs up on what LMTV772 said on switching to ATF... The cold/warm harsh upshifts went away after the change over.

3-2 downshift lurch at stop is still there but a buddy with a Snap-on scanner (transmission computer) checked my truck out and at idle I am showing 3% throttle so I need to try lubing pedal and linkage as discussed in other posts. I replaced both throttle return springs but still have the part throttle at idle. FYI those springs are stock GM part numbers.

OD

 

[sargentwolf]

Story time!

Drove the behemoth to work yesterday. Started out shifting very rough, but about 15 minutes into the trip, it was almost a smooth as driving my jeep. Only really lurches when coasting and has to downshift, going to try lubing the pedal and cables Monday. Next year, Im going to switch to ATF, but for now it seems to be behaving well with the Rural King 15w40 in it.

My boss about had kittens when he saw it. Hes now planning a road trip to a friends farm so we can go offroading in it. Also, for the last few months, I have been emptying out the company storage locker and making dump trips. The last two trip totaled over 2 TONS of junk removed, the majority in the last trip. Got me free lunch and a nice bonus in my pay this week... for gas money...I love my job.

Oh and Im now under orders to bring the behemoth in Friday as the company is getting interviewed for a new contract...the interviewing company wants to know if we are vet hire/apprenticeship friendly...what better way to show we are then a vet intern driving a former military truck?

Pretty good week for once!

 

[Lmtv772]

Awesome, I'm glad you are enjoying your truck. As the oil heats up it will be more fluid , hence the smoother shifts.
Changing the transmission fluid was one of the best things , I've done so far and I wouldn't have it it wasn't thanks to Overdrives' advice and write up. It made it really straight forward