DerekTheGreat
Forum Regular
Hey everyone, long time no chat!
We begrudgingly sold/traded our C3500 for some cash and an old Ferd F250... It wasn't long until we got our next project though, a 1989 Chevy K1500. I'll see about getting some pictures uploaded soon. Anyway here's the issue:
When the trans fluid (Stickshift, believe it to be the oddball Getrag 5LM60 with the 4.00 first gear.) gets hot and with the engine idling in neutral you can hear it knocking, sounds either like a "clack clack clack" or pretty guttural, like rod knock. I actually thought it was rod knock up until one day I put my foot on the clutch and the noise went away. What is it? We've put over 2,500 miles on it so far with no issues and it goes away over 1,100 rip'ems or so and we don't really hear it when it's in gear. However, it makes a pretty angry noise if you try to throw throttle at it in gear below 1,100 rip'ems, like an angry rattle or something, very similar to what spark knock sounds like but angrier. Truck has 224,000 miles right now so it's no spring chicken. I've had all the fluids changed and am running what it calls for, GM Synchromesh. However, when they first changed the fluid the guy put gear lube in it and it shifted like trash when cold, like our old SM465 did. Once that was drained out and Synchromesh put in it's place it shifted great again but that's when I began to notice the clackity clack. I was thinking of putting a 50/50 mix of that and gear lube in, to help quell the noise, what do you guys think?
Also- Could be related or not but the engine has a really rough idle, almost like a miss yet when you pull the wires one by one I've found there's no dead cylinder, as the idle gets even worse.. Not sure what it is as the engine runs great at slightly higher rpms.
Derek
We begrudgingly sold/traded our C3500 for some cash and an old Ferd F250... It wasn't long until we got our next project though, a 1989 Chevy K1500. I'll see about getting some pictures uploaded soon. Anyway here's the issue:
When the trans fluid (Stickshift, believe it to be the oddball Getrag 5LM60 with the 4.00 first gear.) gets hot and with the engine idling in neutral you can hear it knocking, sounds either like a "clack clack clack" or pretty guttural, like rod knock. I actually thought it was rod knock up until one day I put my foot on the clutch and the noise went away. What is it? We've put over 2,500 miles on it so far with no issues and it goes away over 1,100 rip'ems or so and we don't really hear it when it's in gear. However, it makes a pretty angry noise if you try to throw throttle at it in gear below 1,100 rip'ems, like an angry rattle or something, very similar to what spark knock sounds like but angrier. Truck has 224,000 miles right now so it's no spring chicken. I've had all the fluids changed and am running what it calls for, GM Synchromesh. However, when they first changed the fluid the guy put gear lube in it and it shifted like trash when cold, like our old SM465 did. Once that was drained out and Synchromesh put in it's place it shifted great again but that's when I began to notice the clackity clack. I was thinking of putting a 50/50 mix of that and gear lube in, to help quell the noise, what do you guys think?
Also- Could be related or not but the engine has a really rough idle, almost like a miss yet when you pull the wires one by one I've found there's no dead cylinder, as the idle gets even worse.. Not sure what it is as the engine runs great at slightly higher rpms.
Derek