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my 2001 with auto tranny 47re seems gutless,my diff's are 3.55 with 35" tires.How would you know if the torq convertor is slipping or tranny?Top end of the truck is 85 mph and slow on take off.Is this normal for the specs of my truck?

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Is your speedo recalculated for the bigger tires???:shrug:If not, and your speedo reads 85mph, you're going about as fast as your truck can go based on the bigger tires.:2cents:I sure hope you're not driving like that around me!!:whistle:

Start with the simple things, like fuel and air filters. Then work into something bigger.

  • Owner

Start with the simple things, like fuel and air filters. Then work into something bigger.

I would do this as well. Als overify the speed your traveling with a GPS since your speedometer is most likely skewed with larger tires.

[*]Check for codes

[*]Check fuel pressure from idle to WOT

[*]Make sure you getting into lockup

[*]Overboosting (should show up in the error codes)

I would do this as well. Als overify the speed your traveling with a GPS since your speedometer is most likely skewed with larger tires.

That's what I tried to point out in my prior post!!:smart:

my 2001 with auto tranny 47re seems gutless,my diff's are 3.55 with 35" tires.How would you know if the torq convertor is slipping or tranny?Top end of the truck is 85 mph and slow on take off.Is this normal for the specs of my truck?

Bone stock they aren't gutless...but they aren't fast either. 1st and 2nd are really slow (geared for towing). If your TC is slipping your rpms will rise fast and the engine will race without vehicle speed increasing. If you have a stock or original carter pump then it can't handle the fuel delivery needed for 85 mph, or any speed for that matter (carter pumps are only useful as a backup). First diesel?

Just remember, if the truck runs smooth with no smoke but has low power it is a fuel issue. They will run quite well with not much fuel.

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fuel press 18 idle &13 wot(fass ddrp2 pump)showing no codeswhen I floor it rpm goes up to 2600 rpm and ramp speed is slowhow can I check for lockup?can the band be slipping in the tranny?would a smarty be a good thing for the tranny shifting?

I would get it running correctly before modifying it, or at least get a positive ID on the problem and upgrade that component only. Sometime there will be codes without a CEL, so you should use a scanner to check.

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I'll check for codes,if no codes I'll bring it to the tranny shop to check the pressures unless there's a way to check the lock up

With 35's and being stock and w/ the 47RE................................Do we need to go further??!!:shrug::2cents::duh: Just saying!!:smart: And I'm most likely "wrong"!!!So have at it!!!!!!:2cents::smart::thumb1:

I don't know what converter you have, but flashing 2600 RPM off the line on a 47RE isn't normal. I would agree with the rest that it sounds like a trans problem. Either you aren't getting lockup and/or you aren't getting OD either. What RPM is "flat out" at 85 mph?

With 35's and being stock and w/ the 47RE................................Do we need to go further??!!:shrug::2cents::duh: Just saying!!:smart: And I'm most likely "wrong"!!! So have at it!!!!!!:2cents::smart::thumb1:

I am not sure how those come into play either. I have been in a truck with 35's, 3.55's, and a 47RE and it had no issues. Even being stock it still had 235hp and 460 ft/lbs, that's not hurting in the power department. It doesn't match today's Cummins, but it's plenty of power to do 85 without an issue.
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Sounds to me like your torque converter is going bad. Check the condition and level of the trans fluid. A trans temp gauge would help also because when the converter and other components, IE bands and clutch packs, start to go bad the temp jumps up to over 240 degrees in stop and go driving. You might want to have a reputable transmission shop do a once over.

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Sounds to me like your torque converter is going bad. Check the condition and level of the trans fluid. A trans temp gauge would help also because when the converter and other components, IE bands and clutch packs, start to go bad the temp jumps up to over 240 degrees in stop and go driving. You might want to have a reputable transmission shop do a once over.

I think your right that's probably the best way to go .....Thanks man!!:thumb1:
  • 1 month later...
  • Author

Talked to our tranny guy and he said a shift kit can be installed for $500. but that might kill what's left out of my tranny.How can I troubleshoot problem with lock up or bad TC.Somebody mentioned the tranny would go up to 240 degrees if wore out at what temp does the dummy light flicks on,never seen it come on yet.If I buy a Smarty can I modify the shifting pattern?The tranny as 300,000 km the tranny guy figures it lots of k's for a 47RE.This truck pulled a few campers and not abused,the only thing making it work harder is the 35'

At nearly 200,000 miles I'm guessing your trans has seen its better days. A valve body and torque converter would be the minimum I would do if I was going to put any money into it, otherwise your probably better off just driving it until it gives up its ghost. The only thing a Smarty is going to do for that tired ol dog is help you find that ghost, lol. JR