Slippage after fluid change.

[4C FED]

The truck was shifting pretty good IMO prior to changing the fluid. I punched it from a stop several times (no brake launches) & didn't notice any problems prior to this.

I figured I'd better chang the fluid & filter since I didn't know how old it was. It was quite smelly, so I'm sure it was old & abused. Also found 2 filter o-rings stuck in the pickup bore. :roll:
I put the Mobilfluid with a bottle of Lubeguard in noticed & little softer shift. Still shifted quickly, just a little softer. Didn't beat on it cause I didn't have the trans cooler in yet & didn't try a hard acceleration from a stop.

Next weekend I installed the trans cooler & figured I'd give it a test run. Well from a dig it slipped so bad into 2nd I let off & ended that test.
Got home, dumped the Mobilfluid & put in tried & true Type F, ran the motor for a bit with the cooler return line disconnected to pump out as much of the Mobilfluid as possible & added a bottle of Lubeguard. Same deal, still slips if I get on it.

So what do you think could cause this? Stuck TV valve, bad filter, burnt something?
FYI, I'm pretty sure this trans is bone stock.

I've got another complete valve body that is completely updated with all the fixes, should I swap it out?

 

[George Blake]

Re: Slippage after fluid change.

You have to do a pressure check to see what's going on. Mobile synthetic is bad news. Also, wrong type of lubegard can cause problems. It's possible too that the trans just wore out at the same time. I know it sucks but it's possible.:tdown:

 

[gkrcr882]

Re: Slippage after fluid change.

The general consensus is that synthetics should be avoided with these transmissions. There might also be some crud in the transmission clogging things up and making the truck act funny. Worst case scenerio the clutches are burnt up and it's time for a rebuild. If you do need a rebuild, be sure to flush out the cooler(s) to avoid pumping debris and nasty fluid into a new trans.

 

[4C FED]

Re: Slippage after fluid change.

You have to do a pressure check to see what's going on. Mobile synthetic is bad news. Also, wrong type of lubegard can cause problems. It's possible too that the trans just wore out at the same time. I know it sucks but it's possible.:tdown:

Yesh, I know about the synthetic issues. That's why I specifically stayed away from the synthetic lube.
It wasn't the Mobil synthetic. I'm not sure it is or isn't synthetic as it's not indicated in the product description. It was Mobilfluid 424 tractor fluid that a lot of the Buick guys run.
http://www.mobil.com/USA-English/Lubes/PDS/GLXXENCVLMOMobilfluid_424.asp

 

[sytydvr]

Re: Slippage after fluid change.

that has happened to me before this is what happens if you dont replace your oil at the correct interval the oil burns up and imbedes on the clutches when you replace the oil the new stuff is clean and the clutches slip a lot all you need to do is add a bottle of trans X and it will remove all the varnish from the clutches and other parts

http://www.partsamerica.com/ProductDetail.aspx?categorycode=2129&mfrcode=KNW&mfrpartnumber=402035

if it was working before this is the culprit to the problem trust me

let me know what happens

 

[4C FED]

Re: Slippage after fluid change.

Thanks, I'll give that a try today.

 

[George Blake]

Re: Slippage after fluid change.

Why did you use tractor fluid in it? Different clutches will sometime require different fluids. For example, kevlar clutches require a special Chrysler fluid. BW high energy, altos, blues, and hoosier reds all want DexronIII or Type F. Just because someone else used it in a different kind of trans, I wouldn't do it. Lubegard wasn't really designed for that fluid. In the Lubegard information packets I get, it specifically states that they must be used with the intended fluid from the label. The clutch material, calibration and line pressure are what determines longevity of the trans. Experimenting with fluid is not really worth it.

 

[George Blake]

Re: Slippage after fluid change.

It is particularly well suited for reducing wet brake and Power Take-Off (PTO) chatter.

Suitable for commercial transmission applications requiring Type A (Suffix A), Dexron and Type F fluids. Do not use in passenger car automatic transmissions

See these statements?
This fluid doubles as hydraulic fluid. You know how it helps with the chatter? It makes it slip instead of chattering until heat builds up and it catches. They use this stuff in the PTO transfer cases on our Sutphins at work. It's meant for a shift and hold clutch. 700r4 have dynamic clutches meaning they are always cycling on and off. This was never meant to be used in a transmission. I couldn't even venture to say what it did when it mixed with the lubegard.

Since your clutches are saturated, try the Trans-X with some cheap type F. Run this through for a while and then pump the stuff out and do it again. Hopefully the Trans X will displace the other stuff you put in there.

 

[4C FED]

Re: Slippage after fluid change.

I won't try to defend it or explain why. It could be described as why the first users tried Mobil synthetic fluid.
I guess I'll chalk this up as a potentially expensive learning experience.

Listen up noob's... Don't be stupid and learn from my stupidity. :squint:

 

[4C FED]

Update: Slippage after fluid change.

Update: Slippage after fluid change.

Last weekend I drained the fluid, replaced filter and filled with a bottle of TransX & Type F fluid.
While I was at it I replaced the 1-2 accumulator piston & spring with a pinless accumlutaor & white accumulator spring. It was easy to access so I figured it wouldn't hurt.

I noticed a marked improvement in shift feel as soon as I drove it. After 500 miles the terrible slip shift is almost entirely all gone. I plan to dump fluid again & add 1/2 bottle of TransX put another 500 miles on & switch to just Type F.

:woot: Looks like I have dodged the :1gun:

 

[Foot Performance]

Re: Slippage after fluid change.

i think if i drop the pan again i would put an after market boost valve in it to raise line pressure and give it a little extra grab on the clutches

 

[myclone]

Re: Slippage after fluid change.

Why did you use tractor fluid in it?

Some of the GN trans gurus have used the stuff for quite a while. Dunno why, when, or how they discovered it but some ppl swear by it for the 200R.

Never tried it myself since the ppl that recommend it are in the business of selling rebuilds which struck me as odd.....but there are quite a few ppl in that community that run nothing but the tractor lube :dunno:

 

[George Blake]

Re: Slippage after fluid change.

Everyone I've been contacted by that has used it, have nothing good to say about it. Most of the time the response it "it shifts weird. It'll rev way up and hit hard." That same line keeps coming up. I talked with Rossler about it and he didn't understand the point either. You cannot change the characteristics of the clutch material itself by putting another fluid on it. But you can burn the material up if you put the wrong fluid on it and allow it to slip because the fluid developes shear by building up heat. Not good for a passenger vehicle transmission.

 

[George Blake]

Re: Slippage after fluid change.

i think if i drop the pan again i would put an after market boost valve in it to raise line pressure and give it a little extra grab on the clutches

Much better way to get more grab.
The Transgo Jr kit also has a different accumulator valve spring and a different line bias spring to give a little more grab also without getting to crazy.