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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4291
Experience:  Owner at DJ Wilson
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I have a 2010 387 Peterbilt with a 10 speed eaton ultrashift

Customer Question

I have a 2010 387 Peterbilt with a 10 speed eaton ultrashift transmission. We were stuck up in Fife, Washington. Sitting at a Walmart idling all day. When we went to leave I put it in gear and the Transmission service light came on and wouldn't let us go forward or back. I turned the key a few times and got code 27. Code 27 is for clutch disengagement out of calibration. I tried to reset the code by turning the key and then by disconnecting the battery for an hour. Both didn't worked. I shut the truck down for about three hours and took a nap. When I got up, I fired the truck up and it went right into gear and I left. Later that day I was still sitting around truck idling and few hours go by and put it in drive it moved then I backed up. A few hours later I put it in drive and the service light came on and it wouldn't go just the service light blinking and got code 27 again. Shut it off and checked the fluid it was good pulled a few wires of just to check them, they all looked good. I went to washed up and came back 15min at most fired it up and it went right into gear. Drove to the Peter dealer and had them look at it about a hundred dollars later they told me what I already know its a code 27 but they had it as inactive. Said they checked the RPM's everything checked out. So know to the point. They now tell me that the next step is to pull the transmission and check if the clutch is good. They tell me is a 22 hour job and they charge $125 an hour. So to take it out and put it back just to see if the clutch is good it will cost $2,750.00 of course if it is worn they would fix it with a clutch at $1,700 plus any extras. Ok fine if that's the problem it is what it is. But there not even sure that's the problem. By the way last week i just replaced a turbo at about $6,000.00, Point is if I knew that was what it needed i would have it done but to spend $2,750 just to see? Not even sure why its a 22 hour job. I'm now looking at pulling it myself, but before I do all that. I'm I missing something? Other then those two times it runs good. Shifts fine even when i come to a stop or start out. I have had it one year and there's no differences from the day i bought it other then this. Truck has 715,000+ miles. Would replace the clutch soon anyways but after the turbo the took the rest of the slush fund. Again if it is the clutch fine I will replace it but just want to know what else I should check first. How do i know that it's not electrical? Anythoughts?
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 4 months ago.

Hi Dennis, My name is***** will be glad to help. Please post the model number of your transmission from the ID tag.

Expert:  Daniel Wilson replied 4 months ago.

Fault Code 27 - Clutch Disengagement

1. Key on.

2.Start engine.

3.Confirm transmission is in neutral.

4.Raise engine speed above 1500 RPM and allow

engine to return to idle.

5.Compare engine RPM to input shaft RPM with ServiceRanger, a PC-based Service Tool.


Engine idle must be 700 RPM or lower.

•If the speeds match at idle and Fault Code 27 is Active, replace the clutch. Go to



•If they do not match, test complete.

1.Key off.

2.Reconnect all connectors and the negative battery


3.Key on.

4.Clear codes, see “Fault Code

Retrieval/Clearing” on

page 5.

5.Drive vehicle and attempt to reset the code.

6.Check for fault codes, “Fault Code Retrieval/Clearing” on page 5

If Fault Code 27 appears go to




to find error in testing.

If code other than 27 appears, See “Fault

Code Isolation Procedure Index” on page 8.

Expert:  Daniel Wilson replied 4 months ago.

Click this link and see PDF page 95.


Customer: replied 4 months ago.
Thank you but this is no help. As I told you in my question this much is already done. They checked the RPMS already. Thanks but I guess this is what you get when you try to buy answers of the Internet confusion and not a lot of help.

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