Trans Question - Rough shift 1st and 2nd gear

[dwinters14]

Hi all!

I just bought an 03 Yukon 5.3L RWD with 198K miles on it. I feel like i got a pretty clean truck and I'm happy with it. I'm also a perfectionist who has an overactive butt dyno that thinks every like squeak, clunk or boom is the car about to explode.

So I've noticed that the trucks shifts roughly from 1st to 2nd (around 20 mph) and then from second to 3rd (around 30 - 40 mph). But otherwise the truck drives smooth as butter and has no problems dropping into medium throttle or full throttle when I need it.

I did some research and it seems the TPS/Throttle body are known to cause these issues. All the gauges are dead center once the truck is warmed up and everything feels fine.


Do you recommend I change the TPS and clean the throttle body to start? I'll check fluid levels and try and peek under the truck to get a look at the trans as well to make sure nothings leaking.

 

[swathdiver]

Hi all!

I just bought an 03 Yukon 5.3L RWD with 198K miles on it. I feel like i got a pretty clean truck and I'm happy with it. I'm also a perfectionist who has an overactive butt dyno that thinks every like squeak, clunk or boom is the car about to explode.

So I've noticed that the trucks shifts roughly from 1st to 2nd (around 20 mph) and then from second to 3rd (around 30 - 40 mph). But otherwise the truck drives smooth as butter and has no problems dropping into medium throttle or full throttle when I need it.

I did some research and it seems the TPS/Throttle body are known to cause these issues. All the gauges are dead center once the truck is warmed up and everything feels fine.


Do you recommend I change the TPS and clean the throttle body to start? I'll check fluid levels and try and peek under the truck to get a look at the trans as well to make sure nothings leaking.

Welcome Dee! Don't know the answer to your question but others will be along soon enough. Got any pics of the truck yet?

 

[RaiderRodney]

Define "roughly" for us. Reason asking, many people upgrade to a corvette servo in these transmissions to make them shift firmer in 1-2 & 2-3. The normal "smooth" shifting is actually the transmission slipping which can lead to premature wear and failures. The previous owner may have upgraded the servo and be the reason you're feeling firmer shifts early in the gearbox. Any way you could get in touch with them to ask?

 

[OR VietVet]

Define "roughly" for us. Reason asking, many people upgrade to a corvette servo in these transmissions to make them shift firmer in 1-2 & 2-3. The normal "smooth" shifting is actually the transmission slipping which can lead to premature wear and failures. The previous owner may have upgraded the servo and be the reason you're feeling firmer shifts early in the gearbox. Any way you could get in touch with them to ask?

I was thinking the same thing. My Corvette servo firmed up the shifts. They shift harder and that is fine with me. What does the fluid look like? Is it full? Any maintenance records when bought rig.

Also, Welcome to the forum from Oregon and post pics. Another also:


We recommend that you put all your rig(s) info in your signature so we all don’t have to guess at year, make, model, engine size, trans, rear axle locker…….etc. While you may have posted pertinent info in your first post, you may forget to do it again and the info is needed by us anyway. Makes it way easier on all members that attempt to help, to have that info right up front. It is also recommended that you take a pic of your RPO codes, on the inside cover of the glove box, and post that image in your signature. All this info will greatly help those that will try to help with a problem.


If there is any other info, like upgrades, mods or recent mechanical/maintenance work done, that would be helpful in any post as well. Too many times a question is asked by the poster and after about 10 responses we find out that the poster has done recent work to attempt to fix the problem or work that was done that SEEMS not related to the problem.

 

[dwinters14]

Welcome Dee! Don't know the answer to your question but others will be along soon enough. Got any pics of the truck yet?

Define "roughly" for us. Reason asking, many people upgrade to a corvette servo in these transmissions to make them shift firmer in 1-2 & 2-3. The normal "smooth" shifting is actually the transmission slipping which can lead to premature wear and failures. The previous owner may have upgraded the servo and be the reason you're feeling firmer shifts early in the gearbox. Any way you could get in touch with them to ask?

It'll hang high in the revs, and then shift and it's a bit clunky. I just drove it today and it was a lot smoother so I'm not too sure. The previous owner had the truck for less than 1k miles so if someone did do it, it would have been a few years ago.

I was thinking the same thing. My Corvette servo firmed up the shifts. They shift harder and that is fine with me. What does the fluid look like? Is it full? Any maintenance records when bought rig.

Also, Welcome to the forum from Oregon and post pics. Another also:


We recommend that you put all your rig(s) info in your signature so we all don’t have to guess at year, make, model, engine size, trans, rear axle locker…….etc. While you may have posted pertinent info in your first post, you may forget to do it again and the info is needed by us anyway. Makes it way easier on all members that attempt to help, to have that info right up front. It is also recommended that you take a pic of your RPO codes, on the inside cover of the glove box, and post that image in your signature. All this info will greatly help those that will try to help with a problem.


If there is any other info, like upgrades, mods or recent mechanical/maintenance work done, that would be helpful in any post as well. Too many times a question is asked by the poster and after about 10 responses we find out that the poster has done recent work to attempt to fix the problem or work that was done that SEEMS not related to the problem.

Once I get my tags I'm going to her up on the lift and check all fluids and the under body as well as flush everything with new stuff. As far as I know only maintenance work has been done and I don't have any records besides the carfax. The truck is clean and my butt thought everything felt fine on the test drive so I bought it! There is a bit of a whine which sounds like it could be the tranny on a cold start, but it goes away once warmed up.

I'll look up all the detailed info on the truck for my sig, because I honestly have no idea what model trans/5.3L i have as well as the rear axle lock.

 

[OR VietVet]

Hopefully @rockola1971 will chime in with his transmission expertise.

 

[swathdiver]

View attachment 251968 View attachment 251969



It'll hang high in the revs, and then shift and it's a bit clunky. I just drove it today and it was a lot smoother so I'm not too sure. The previous owner had the truck for less than 1k miles so if someone did do it, it would have been a few years ago.



Once I get my tags I'm going to her up on the lift and check all fluids and the under body as well as flush everything with new stuff. As far as I know only maintenance work has been done and I don't have any records besides the carfax. The truck is clean and my butt thought everything felt fine on the test drive so I bought it! There is a bit of a whine which sounds like it could be the tranny on a cold start, but it goes away once warmed up.

I'll look up all the detailed info on the truck for my sig, because I honestly have no idea what model trans/5.3L i have as well as the rear axle lock. View attachment 251970 View attachment 251971

Looks really clean for a truck almost old enough to vote!

 

[dwinters14]

Looks really clean for a truck almost old enough to vote!

Thank you! I feel like I got a good one (don't wanna jinx it!) but the A/C blows cold, she starts right up and is comfy so I'm a happy camper!

 

[Tonyrodz]

View attachment 251968 View attachment 251969



It'll hang high in the revs, and then shift and it's a bit clunky. I just drove it today and it was a lot smoother so I'm not too sure. The previous owner had the truck for less than 1k miles so if someone did do it, it would have been a few years ago.



Once I get my tags I'm going to her up on the lift and check all fluids and the under body as well as flush everything with new stuff. As far as I know only maintenance work has been done and I don't have any records besides the carfax. The truck is clean and my butt thought everything felt fine on the test drive so I bought it! There is a bit of a whine which sounds like it could be the tranny on a cold start, but it goes away once warmed up.

I'll look up all the detailed info on the truck for my sig, because I honestly have no idea what model trans/5.3L i have as well as the rear axle lock. View attachment 251970 View attachment 251971

Kind of like this? I have a shift kit and Corvette servo.

Your rpos in your glovebox will tell you what you have. Trans is a 4L60, you most likely have the 5.3 too. It'll also tell you what rear ratio you have.

 

[dwinters14]

Kind of like this? I have a shift kit and Corvette servo.

Your rpos in your glovebox will tell you what you have. Trans is a 4L60, you most likely have the 5.3 too. It'll also tell you what rear ratio you have.

Yes, just like that. I'll check that out tonight and report back. Also my eyes aren't warm to these trucks yet, but does my suspension look sagged?

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