"Spring Cleaning" Sad Days....

[monteperformanc]

I have been following this board closely since I bought my first GN last year. It seems everyone here swears by doing the "Spring Cleaning" routine. I have been going through that process and I seem to have killed my transmission (16,500 orig miles) by changing the fluid. It was shifting perfectly before. Actually even better then I thought a stock trans could shift. Chirped second and third. About 25 miles after changing the fluid and filter, I now have a lazy 1-2 shift, and a flare on the 2-3. I spoke with a Trans builder on the board and he pretty much confirmed that putting new fluid in an old trans is a very bad idea. Just wanted to put this out as a warning to those who have thought about changing their fluid. :frown:

 

[davidf]

Thats still unusual in my book. Maybe a high mileage trans. but a very low mileage? I've serviced many trannies including convertor flush even on higher mileage cars in the past with zero issues so far. Maybe I've just been lucky.

 

[aminga]

That seems highly unlikley unless the filter didn't get seated or something similar.

 

[monteperformanc]

The new filter had a band with ridges on the neck while the old filter had an o-ring. The new one didn't really seem to click into place like the old one did. It's in, but it just feels different. Perhaps that is the issue? Car ran fine for about 25 miles and then all of a sudden the flare started. I bought another new filter today, and I'm going to change it again to see if there is any difference. But I have heard from a few different people now that the high detergency of new fluid will cause problems in an old transmission.

 

[IrvJr]

The band with ridges is the o ring, it just comes already on the filter. I doubt the fluid would cause an overnight failure, something else is a miss.

 

[TurboBob]

make sure your TV cable is set right,

look at the old filter and both the replacements and make sure you get a good seal and the the filter is properly seated.

There was a rumor years ago that some of the filters were sucking air around the crimp also.

Make sure you over-fill the trans once you are done.

If its still soft when you are done, borrow or buy a pressure gauge and see what the pressures are doing.

Bob

 

[davidf]

What fluid are you using? In my opinion, "old" trans. means "high mileage", when the old fluid has varnished itself on the clutches then the newer high detergent fluid basically washes off the varnish causing slippage.

 

[LOT]

slippage

I'm curious as the how this turns out. I would be shocked that fresh fluid has caused your problem. Are you SURE it is not low on fluid. IMO, it is either low on fluid or sucking air,for whatever reason.

 

[JOHNDEEREGN]

Have to agree with the guys here as well. I am no tranny builder but service my tranny's very regular and have never had any issues.

Good luck with your findings.

 

[gnmaster2004]

Are you sure there wasnt another o-ring on the old filter that was stuck in the pump. Maybe when you put the new filter in it pushed the other o-ring into the pump. Some guys use a double o-ring to seal the filter.

 

[monteperformanc]

I am going to drop the pan either tonight or tomorrow so I'll see what's going on with the filter. I definitely removed the old o-ring because it did get stuck in the trans and I had to reach in and pull it out. I just remember the new filter felt different going in. Does the filter with the grooved band "snap" in solidly? I had problems with that. I used type F fluid. The TV cable is fine as far as I know. I have not touched it, but it's still connected and not broken or anything. The fluid was right at the full mark the day after I changed it. When I checked it last night, it looked over-full, like almost an inch past the full mark.

Let me ask this, lets say the filter caused this somehow, will putting a proper filter in place fix it, or is the damage already done anyway?

 

[bmackinnon]

If you haven't driven it much or hard, I'm gonna' guess it will be fine.... like LOT said, must be sucking air somehow.... I remember way back when reading on gnttype about the 'crimp' on some of the filters were bad and caused problems.... use a genuine oem AC Delco filter.... lots of archived chatter about this over there... Changing the fluid will NOT ruin the trans/cause slippage, in itself....

 

[dsa87gn]

Im no tranny expert but, If your fluid doesnt have a nasty burnt smell you probably will be ok with a proper filter replacement/fluid change.

When i started modding my car, cranking up boost and added drag radials, my 40k mile tranny started slipping at the 1/2 shift. The fluid had a slight burnt smell. I put a shift kit in and changed fluid/filter and it has been perfect for another 8K miles so far. Good luck

 

[turbodave231]

My professional opinion is that the "New fluid in and old transmission will cause failure" is a load of fertilizer. I've serviced 100's of older transmissions and never had this problem occur. Failure after fluid service indicates that a problem already existed. The post-mortem usually shows the bad parts (not caused by new fluid).

I'll bet you'll find that something else is causing the problem. Bad filter, air intrusion, low fluid etc.

 

[hesermon]

I used type F fluid.

Do you know something that I don't about fluid? Type F fluid is for Ford vehicles. Our cars should use Dex III or more commonly known now as "Dex/Merc" Pretty sure I'm right on this but always willing to learn!

 

[Sweetwater GN]

You can use type F for 'firmer' shifts, but I drained the entire system including the TC of the Dex first.

 

[IrvJr]

I have heard many people use Type F for firmer shifts. I would never use it. Sure you get firmer shifts but it has less lubricants too so you lose service life. Now if its just a race car and not driven much on the streets then fine, but if its a street car or dd then i would use Dex III or the new Dex VI im gonna try the next flush.

 

[notacarlo]

I'd be willing to bet when you pull the pan the filter is sitting in it. Breach in the fluid feed circuit.

 

[Just a Six??]

Are you sure there wasnt another o-ring on the old filter that was stuck in the pump. Maybe when you put the new filter in it pushed the other o-ring into the pump. Some guys use a double o-ring to seal the filter.

Common mistake.

 

[Just a Six??]

I have heard many people use Type F for firmer shifts. I would never use it. Sure you get firmer shifts but it has less lubricants too so you lose service life. Now if its just a race car and not driven much on the streets then fine, but if its a street car or dd then i would use Dex III or the new Dex VI im gonna try the next flush.

1/3 type F not 100% My billet tranny builder said NO type F if you want a warranty.
Some still use a few quarts but thats about it.