Gain extra benefits by becoming a Supporting Member Click here find out how!
Classic Performance Products Classic Parts
American Auto Wire Classic Industries
Chevs of the 40sDanchuk Catalog
Hellwig Products IncPerformance Rod & CustomEcklers AutoMotive
Nu-Relics Power Windows
Impala Bob's Bob's Chevy Trucks Bob's Chevelle Parts Bob's Classic Chevy



Username Post: 4L60E Hard Shifts        (Topic#80868)
kingb36 
Member
Posts: 6
kingb36
Loc: Bass Lake IN
Reg: 11-13-04
11-13-04 08:53 PM - Post#552070    

My daughter has a 93 C1500 W/T 4.3. The 4L60E has suddenly started to make a very hard 1-2 shift. Other shifts are slightly harder than what has been normal, but the 1-2 bangs really hard.

I've checked fluid levels and condition, both are normal, fluid not burnt, nothing abnormal in the trans/engine mounts or u-joints. No other obvious electrical issues or performance problems. Electrical connectors at trans and throttle clean with no corrosion.

Having limited experience with this trans, I'm not sure where to look further at this.

Anyone have any ideas where to go with this or anything I have overlooked? All help is appreciated.

1985 Taylor LP 20' / Berkeley F JetDrive / 454 1974 Chevelle / 400 1993 C1500 WT / 4.3 1964 Impala SS / 409-425 (Under Construction)


 
someotherguy 
Senior Moderator
Posts: 28964
someotherguy
Age: 49
Loc: Texas
Reg: 08-01-03
Re: 4L60E Hard Shifts
11-13-04 10:14 PM - Post#552071    
    In response to kingb36

Howdy king and welcome to CT,

I will bet a code scan of the truck shows a P1870, there is a kit to fix this problem with your transmission. It detected slipping and upped line pressure to full in an attempt to prevent further slipping and damage.

This is an common problem with the 4L60 trans, you can search this forum on P1870 and you'll find lots of info.

Best to get it fixed before the trans gets hurt!

Richard

06 Silverado ISS / 06 Silverado SS / 06 300C SRT8


 
transman618 
Senior Member
Posts: 839
transman618
Loc: Cumming,GA
Reg: 06-06-04
Re: 4L60E Hard Shifts
11-14-04 03:15 AM - Post#552072    
    In response to kingb36

Like Richard said, get it scanned and see if any codes come up. Since you are feeling harsh shifts other than just the 1-2 it sounds like a code has been set and the computer has commanded the EPC (Electronic Pressure Control) solenoid to full line pressure. With the 1-2 feeling more harsh than the other, well, several common problems I see in these transmissions when they cross my bench will cause a harsh 1-2. One being a worn 1-2 accumulator piston and another is a worn valve body separator plate. The separator plates wear where the check balls are. The 1-2 shift check ball I commonly see either jammed in the separator plate or worn completely through the plate and sitting in the worm tracks in the case. These check balls just hammer on the separator plate wearing it out. With the accumulator pistons, they are aluminum pistons. The pin which the piston rides on is steel and commonly wears the pin bore into an egg shaped hole. The accumulator then leaks and causes a harsh 1-2. The purpose of the accumulator is to cushion the shift. If the accumulator is leaking there is no or reduced cushion effect giving you a harsh shift. Get the computer scanned and post back with the code(s). If you do get the P1870 code which is very common in these transmissions you are looking at valve body repair to fix it. If there are a lot of miles on the trans, you might want to consider an overhaul now because a valve job will cost close to half of the price to overhaul anyway.

GM MASTER TECHNICIAN
SR. TRANSMISSION BUILDER



 
notcamero 
Senior Member
Posts: 953

Reg: 08-02-03
Re: 4L60E Hard Shifts
11-14-04 06:06 AM - Post#552073    
    In response to transman618

Will he get this type of code with a 93? Anyway take a look at the throttle area on the engine and make sure there is not a cable going to the transmission. Many 93s that I've seen did not have an E trans. If this has the TV cable, that's where to start, check adjustment. If no cable disregard all this and I apologize for wasting space.



 
kingb36 
Member
Posts: 6
kingb36
Loc: Bass Lake IN
Reg: 11-13-04
Re: 4L60E Hard Shifts
11-14-04 01:58 PM - Post#552074    
    In response to notcamero

Thanks to everyone for all the info.

There is no TV cable, which my Haynes manual <barf> tells me is a 4L60E. I'm sure it's the original trans.

I was wondering about the codes as well. From previous problems I have used the connector under the dash in conjunction with the "check engine" light to pull out some 2 digit codes. Is there a scanner that will access additional codes from this computer, or is that only for OBD II?

I'm not sure that this truck is worth investing in a trans overhaul at 160K mi. I was wondering what would be involved in swapping either a 350 or 400 Turbo besides adapting the VSS? Is either one a direct mechanical swap?

Thanks again for your input, you guys have a great forum here!

1985 Taylor LP 20' / Berkeley F JetDrive / 454 1974 Chevelle / 400 1993 C1500 WT / 4.3 1964 Impala SS / 409-425 (Under Construction)


 
kingb36 
Member
Posts: 6
kingb36
Loc: Bass Lake IN
Reg: 11-13-04
Re: 4L60E Hard Shifts
11-15-04 09:49 AM - Post#552075    
    In response to kingb36

Another thought, could the computer have sensed slipage due to a low fluid condition and upped the line pressure, and is there any way to clear/reset the computer and see if this occurs again?

1985 Taylor LP 20' / Berkeley F JetDrive / 454 1974 Chevelle / 400 1993 C1500 WT / 4.3 1964 Impala SS / 409-425 (Under Construction)


 
brad_bb 
Valued Contributor
Posts: 4260
brad_bb
Loc: Joliet, IL.
Reg: 07-13-01
Re: 4L60E Hard Shifts
11-15-04 09:59 AM - Post#552076    
    In response to kingb36

If you end up being in the market for a remanufactured trans I encourage you to check out Roadmaster transmissions (aka Dr. Evil performance transmissions) in Schaumburg, IL. They ship all over and advertise on ebay sometimes. Nice shop and a lot of experience. I wrote extensively about my experience a few months back in the Vendor stories forum.

If someone else can design it, I sure as heck can figure out how to fix it!


 
chrisk1500 
Very Senior Member
Posts: 1819
chrisk1500
Loc: Saskatchewan, Canada
Reg: 10-30-04
Re: 4L60E Hard Shifts
11-15-04 10:41 AM - Post#552077    
    In response to kingb36

I don't think you will get a code P1870. This is not an OBD II truck. You have the OBD I. What 2 digit codes are you getting?? Check out this site :http://www.troublecodes.net/GM/
It will give you some insight towards any codes that you do get. If you think that clearing the codes will help, do so by disconnecting the battery for a few minutes. I know that transman618 and someotherguy have a lot of experience, but I think that they looked past the point that your truck is a 93, and as such you won't find code P1870, rather it will be a two digit code such as 66 or 69.

07.5 DMAX 2500 HD ext cab, 4x4, Edge EVO Race, 4" straight pipe, PPE tie rod sleeves, bushwhacker pocket flares, etc...13 second farm truck!

06 Escalade

15 Sierra - Kodiak Edition


 
chrisk1500 
Very Senior Member
Posts: 1819
chrisk1500
Loc: Saskatchewan, Canada
Reg: 10-30-04
Re: 4L60E Hard Shifts
11-15-04 11:22 AM - Post#552078    
    In response to chrisk1500

Better yet, see this site and pay attention to Fig. 3 and Fig. 4

http://www.autozone.com/servlet/UiBroker...23d80087037.jsp

07.5 DMAX 2500 HD ext cab, 4x4, Edge EVO Race, 4" straight pipe, PPE tie rod sleeves, bushwhacker pocket flares, etc...13 second farm truck!

06 Escalade

15 Sierra - Kodiak Edition


 
transman618 
Senior Member
Posts: 839
transman618
Loc: Cumming,GA
Reg: 06-06-04
Re: 4L60E Hard Shifts
11-15-04 11:51 AM - Post#552079    
    In response to chrisk1500

You're right , I wasn't paying attention to the year when I first read the post.

A 93 definately will not set a "P" code. It will though have the same valve body problem that a OBDII 4L60E will have. The valve body along with the accumulator on this transmission needs to be looked at.



transman

GM MASTER TECHNICIAN
SR. TRANSMISSION BUILDER



 
kingb36 
Member
Posts: 6
kingb36
Loc: Bass Lake IN
Reg: 11-13-04
Re: 4L60E Hard Shifts
11-15-04 02:37 PM - Post#552080    
    In response to transman618

Thanks again for the additional info.

As the truck isn't here during the week, I wont be able to check the codes until this weekend. I'll post up then and let you know what I find. In the mean time, shes borrowing a car to keep the miles down until we figure out what to do.

Brad, thanks for the info on the trans shop. As the truck is in Chicago during the week I'll definately check with them on a rebuilt as I prefer to do business close to home on something like this.

Anyone have any thoughts/ideas on the T350/400 swap, or is it just not a practical option?

1985 Taylor LP 20' / Berkeley F JetDrive / 454 1974 Chevelle / 400 1993 C1500 WT / 4.3 1964 Impala SS / 409-425 (Under Construction)


 
someotherguy 
Senior Moderator
Posts: 28964
someotherguy
Age: 49
Loc: Texas
Reg: 08-01-03
Re: 4L60E Hard Shifts
11-15-04 02:45 PM - Post#552081    
    In response to chrisk1500

Chris:

I don't have a bunch of experience.. and yeah, I overlooked the year as well on the '93. But as transman said, it's a 4L60E, it has the same issue as the later ones.

Wonder when we're gonna get a sticky post "Common problems in these trucks" in this forum? Who decides/starts it?

* 4L60E 1-2 hard shift
* Wiper motor problems
* Door hinge pins
* Blower motor only runs on high speed
* Fuel pump diagnosing & replacement
etc..

Richard

06 Silverado ISS / 06 Silverado SS / 06 300C SRT8


 
chrisk1500 
Very Senior Member
Posts: 1819
chrisk1500
Loc: Saskatchewan, Canada
Reg: 10-30-04
Re: 4L60E Hard Shifts
11-15-04 02:56 PM - Post#552082    
    In response to someotherguy

Agreed, the trans will have the same problem, but the code it trips will be a little different

07.5 DMAX 2500 HD ext cab, 4x4, Edge EVO Race, 4" straight pipe, PPE tie rod sleeves, bushwhacker pocket flares, etc...13 second farm truck!

06 Escalade

15 Sierra - Kodiak Edition


 
Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

34119 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.084 seconds.   Total Queries: 13   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 02:21 PM
Top