Tranny problems?

sethc24 · Apr 19, 2012

When i am driving along at 50 km/h and i am in overdrive on a hill, I step into the throttle a little bit but instead of powering up the hill something unlocks and the rpms shoot up suddenly and the truck has a lot less power. It does this constantly in overdrive and when the truck downshifts on a hill.

Truck is a 2000 f250 auto, with a JW valvebody.

Now i know this is something slipping etc in the transmission. But is this a problem with the TQ or the clutch discs inside the tranny?

What would be the symptoms of either one failing?

Mark Kovalsky · Apr 20, 2012

At 50 km/h (32 miles per hour) the transmission should be in third gear with the torque converter unlocked. You are most likely seeing a 3-2 downshift.

If the transmission is really slipping you can tell by sniffing the ATF on the end of the dipstick. If it smells so bad it makes your eyes water and it's brown or black the trans is slipping and needs to be rebuilt. Most likely you are getting a 3-2 downshift that is normal, but not what you like.

JLDickmon · Apr 20, 2012

sethc24 said:
When i am driving along at 50 km/h and i am in overdrive on a hill, I step into the throttle a little bit but instead of powering up the hill something unlocks and the rpms shoot up suddenly and the truck has a lot less power. It does this constantly in overdrive and when the truck downshifts on a hill.

Truck is a 2000 f250 auto, with a JW valvebody.

Now i know this is something slipping etc in the transmission. But is this a problem with the TQ or the clutch discs inside the tranny?

What would be the symptoms of either one failing?

looses power like road speed drops, or
looses power like no matter how far the go pedal is pressed it won't maintain speed or
looses power like it feels like you're standing on the brake..

8inchstroker · Apr 20, 2012

I was thinking of a different tranny

sorry for derail

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sethc24 · Apr 21, 2012

Sorry mistake in original post. I meant 80 km/h not 50.

Feels like your standing on the brake when it looses power.

TARM · Apr 21, 2012

We be's Americans so MPH LOL

When did this start happening? When you installed the JW VB by chance? What size tires are your running? What is rear dif gearing? 3.73 4.10 ?

DO you have nay power mods down to your engine? Chip ? Tow heavy or romp on it a bit?

So what finally happens after you stomp on the pedal and the rpms jump up this should be as it shifts out of OD and into 3rd. What happens after this? Does it just keep slowing till it shifts into second ? Does it eventually start to speed up? what?

Mark Kovalsky · Apr 21, 2012

80 km/h = 50 MPH.

sethc24 · Apr 21, 2012

No it started happening 8 months after i installed the JW valvebody. As for power mods.
Pretty basic. 4'" exhaust TB, 6637 and tuning from TDP. No i dont tow heavy. I romp on it sometimes. Not very much though. Tranny has 98,000 miles on it. Gearing is 3.73.

It downshifts into 3rd and then the rpms surge up and no power. Some power in 3rd gear and then the rpms surge up again and no power. And it repeats this until you back out of the pedal. Best i can describe it. And the truck does speed up eventually too 120 km/h.

The truck in general just seems to lack major power. As for a comparison. Our other truck a 2001 f350 with 7.3 psd, stock auto , 6637 intake and php tuning ( 80 hp dd tune) will absolutely destroy my truck.

And thats running the "street" tune from TDP on my truck.

TARM · Apr 21, 2012

It sounds like your TQ converter is flaring. But I am far from being a tranny experience more like a anti-expert LOL

sethc24 · Apr 21, 2012

Flaring lol? So this is TQ related not the clutch packs in the transmission? &*#^$*& i wish i could afford a bts. Why im hoping lol its the TQ.

So if it is would a converter from ford be okay? Are these triple disc?. Is there a decent TQ for 400-500$ out there.

TARM · Apr 21, 2012

Now again I am just taking a stab. Heed my warning that I am not an expert. But no if you do replace it I would try one of the 3 disc units others are trying; I think they are running under $400. Do a search on here for 3 disc torque converters and you will get the brand. I had it at the tip of my tongue and its gone. :doh:

First you need to be sure its that as if its a clutch pack you still will be out money. I do know that most of the time the first thing to go is the converter then was second gear then a shaft That is from reading way to many threads LOL

But if its the converter you want to get it out before it puts metal into the tranny and cooler. The thing I am wondering about is if it would not be showing up in other gears if it was the converter. Hence why you need someone with a bit more experience than me to confirm things.

Mark Kovalsky · Apr 22, 2012

TARM said:
It sounds like your TQ converter is flaring. But I am far from being a tranny experience more like a anti-expert LOL

That's a new one on me. Could you explain to me what that means?

Mark Kovalsky said:
If the transmission is really slipping you can tell by sniffing the ATF on the end of the dipstick. If it smells so bad it makes your eyes water and it's brown or black the trans is slipping and needs to be rebuilt.

Right there I told you how to determine if your clutches are slipping. Are they?

TyCorr · Apr 22, 2012

Taking into consideration what Mark said, it could be tuning related. Remove.the chip and drive the truck and.see.what happens.

Vengeance · Apr 22, 2012

Easy way to see if something is wrong with the tunes is to swap chips and see how the trucks run.

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TyCorr · Apr 22, 2012

Vengeance said:
Easy way to see if something is wrong with the tunes is to swap chips and see how the trucks run.

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Kinda what I was thinking. Tuning has a huge impact on the trans, imo anyway, and can completely evade the operators trust if its not right(or to their liking).

Vengeance · Apr 22, 2012

Let me know what happens if I need to fix the tunes.

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sethc24 · Apr 22, 2012

Atf fluid level is fine. The atf is a nice pink/red hue and smells like normal atf to me.

As for tuning. The tranny was fine a while back running the same tuning.

sethc24 · Apr 22, 2012

Atf fluid level is fine. The atf is a nice pink/red hue and smells like normal atf to me.

As for tuning. The tranny was fine a while back running the same tuning.