Recently installed a takeout a518 into my 1985 Crew cab W250 4x4. Kept the factory married NP205 transfer case. Pulled the pan, adjusted the bands and new filter before install. Fluid looked new in tranny before filter change. No burnt smell or anything. After the transmission is warmed up, i get a shudder in first gear at low rpm. Shudder stops before 1-2 shift. under heavy throttle, shudder stays till right before the 1-2 shift. light shudder on kickdown under heavy throttle. I'm thinking it may be clutches. Any suggestions?

Does your tranny have a torque converter clutch? If not then my wild guess is clutches.

I know next to nothing about this, but perhaps the oil pump is wearing and not providing enough pressure until the rpm come up? And under big throttle it still isn't enough?

R.

I'm sure someone who actually knows will correct me...............

Does it do it in manual low? (shifter in first gear)

Does this shudder feel like the trans is slipping as first gear is the rear clutches and the sprag (overrunning clutch) holding? Also the direct clutches in the overdrive hold in first , second and third along with the sprag in the overdrive. Is it worse if you step on the gas harder or does the shudder feel more like a vibration type of shudder ? Have you tried manual low like was said ? Ron

Like Nemisis asked "Does it do it in manual low? (shifter in first gear)".

Have not tried it in manual low, will try that this morning and get back with that info. At first i thought it was a ujoint, but all of those seem to be good. Yes, vibration/shudder is worse with more throttle. If it makes a difference, I have not hooked up the overdrive switches yet.

I think you have a band too tight.

Ok, got a chance to check it out. Still has the shudder when shifting manually through the gears.