94 Chevy SCLB C2500 5.7 TBI 4L60E just a little over 150K on it.
The truck spent its entire life here in southern Utah, 1st owner took great care of the truck, i.e. servicing etc...
This is now my friends truck, I've done a tune-up consisting of cap & rotor, plug wires & plugs, oil and filter this was at 152K
Replaced battery and starter, alternator was putting out about 13.9 to 14.1 volts at this time. Test drove the truck and it drove and worked as it should. As of 2 weeks ago.
There are no service records of tranny service nor signs of tranny pan removal for servicing, the truck belonged to an older gentleman who passed and the son stated his dad never pulled anything with the truck, just drove it as a DD. So there's a quick history of the truck.
A couple of days after doing the starter and battery my friend called and said the truck isn't running right, go to his house, cold start, starts up as it should, placed shift lever in D w/circle and off we go, engine and trans are cold still, up shift from 1st to 2nd hard like the tranny had a B&M shift kit put in it, 3rd to 4th not quit as hard on the up shifts, downs shifts are nice and smooth, this was done several times in town driving, continued this with same results until tranny was at operating temp, went to highway driving, shifts at this time where the same, up shifts where somewhat slow and hit hard but shifted all the way up to 4th or over drive, no grinding nosies, no smell of "burnt" tranny fluid, no leaks, while continuing at highway speeds 75mph pulled shift lever down to 3 position and the tranny did as designed to do smooth down shift from over drive to 3rd gear while RPM's increased as expected to.
While exiting highway shift lever still in 3 position down shifts where nice and smooth, still leaving shift lever in same position entering local traffic on surface street up shifts where as stated a little slow and hit hard, my foot on gas pedal remained slow and steady with firm pressure through out the shifting process, I tried this with the shift lever in the D w/ circle, with the same results, up shifts are a little slow and hard, but the down shifts nice and smooth.
No visible signs of external leaks, except for a drip from the speed sensor ( I believe ) at rear of tail shaft on drivers side, no drips or leaks from tail shaft where yoke is, all U-joints are tight, no clunk when going in to reverse or forward positions. I have looked at the wiring going to the tranny and appears to be ok, and no signs of abuse or abnormal wear or chaffing etc...
1- Tranny fluid on dip stick does not smell or look burnt, but is dirty.
2- No signs of gunk build up around electrical plug(s) except for the very small drip from the speed sensor at the rear of tail shaft, I'm not sure if that is what that is called.
3- He as like me are NOT heavy footed, burn rubber drivers, just every day guys going to and from work on our local streets average speed limits of 35 or 45mph roads.
So like the rest of us, not a lot of money to throw at this, and trying to help my friend,
1- Drop tranny fluid and replace w/new fluid and filter.
2- Double check all clean all electrical connections.
3- TPS? is this located on the TBI unit passenger side, and is there a way to test it?
4- The sensor at the rear of tail shaft, can this be tested? The speedo in the gauge cluster works with no fluttering or bouncing what so ever.
Or is this an internal problem? I'm I missing something, all shifting is being done by electronics, there's no vacuum lines to this tranny correct?
Any input or advice on this would be gratefully appreciated, I hoping from the knowledge here that its something simple and not to costly for him, but then again that doesn't always go that way! Thanks for any help!
The truck spent its entire life here in southern Utah, 1st owner took great care of the truck, i.e. servicing etc...
This is now my friends truck, I've done a tune-up consisting of cap & rotor, plug wires & plugs, oil and filter this was at 152K
Replaced battery and starter, alternator was putting out about 13.9 to 14.1 volts at this time. Test drove the truck and it drove and worked as it should. As of 2 weeks ago.
There are no service records of tranny service nor signs of tranny pan removal for servicing, the truck belonged to an older gentleman who passed and the son stated his dad never pulled anything with the truck, just drove it as a DD. So there's a quick history of the truck.
A couple of days after doing the starter and battery my friend called and said the truck isn't running right, go to his house, cold start, starts up as it should, placed shift lever in D w/circle and off we go, engine and trans are cold still, up shift from 1st to 2nd hard like the tranny had a B&M shift kit put in it, 3rd to 4th not quit as hard on the up shifts, downs shifts are nice and smooth, this was done several times in town driving, continued this with same results until tranny was at operating temp, went to highway driving, shifts at this time where the same, up shifts where somewhat slow and hit hard but shifted all the way up to 4th or over drive, no grinding nosies, no smell of "burnt" tranny fluid, no leaks, while continuing at highway speeds 75mph pulled shift lever down to 3 position and the tranny did as designed to do smooth down shift from over drive to 3rd gear while RPM's increased as expected to.
While exiting highway shift lever still in 3 position down shifts where nice and smooth, still leaving shift lever in same position entering local traffic on surface street up shifts where as stated a little slow and hit hard, my foot on gas pedal remained slow and steady with firm pressure through out the shifting process, I tried this with the shift lever in the D w/ circle, with the same results, up shifts are a little slow and hard, but the down shifts nice and smooth.
No visible signs of external leaks, except for a drip from the speed sensor ( I believe ) at rear of tail shaft on drivers side, no drips or leaks from tail shaft where yoke is, all U-joints are tight, no clunk when going in to reverse or forward positions. I have looked at the wiring going to the tranny and appears to be ok, and no signs of abuse or abnormal wear or chaffing etc...
1- Tranny fluid on dip stick does not smell or look burnt, but is dirty.
2- No signs of gunk build up around electrical plug(s) except for the very small drip from the speed sensor at the rear of tail shaft, I'm not sure if that is what that is called.
3- He as like me are NOT heavy footed, burn rubber drivers, just every day guys going to and from work on our local streets average speed limits of 35 or 45mph roads.
So like the rest of us, not a lot of money to throw at this, and trying to help my friend,
1- Drop tranny fluid and replace w/new fluid and filter.
2- Double check all clean all electrical connections.
3- TPS? is this located on the TBI unit passenger side, and is there a way to test it?
4- The sensor at the rear of tail shaft, can this be tested? The speedo in the gauge cluster works with no fluttering or bouncing what so ever.
Or is this an internal problem? I'm I missing something, all shifting is being done by electronics, there's no vacuum lines to this tranny correct?
Any input or advice on this would be gratefully appreciated, I hoping from the knowledge here that its something simple and not to costly for him, but then again that doesn't always go that way! Thanks for any help!
