Transmission Problem?

[Gordy]

Who did the trans flush danger girl?

[
QUOTE=DangerGirl;288432]Not rude at all. I realized going into this that it may end up being a bad tranny but it never hurts to try first. I am currently thinking that is what it is, since there are no codes and I can not find anything but "R&R". Unfortunately, I really do not want to spend the $1200 or so it will cost to rebuild it so I am stuck with a very expensive paperweight at the moment. I was just thinking of selling it "as is" but that seems such a shame since I really do like the truck and don't need to sell. I am just beyond frustrated because it only has 86,000 miles and the tranny should not go out that soon.

---------- Post added at 06:01 PM ---------- Previous post was at 05:48 PM ----------

here is a video of it in action.....maybe it will help.....

http://www.youtube.com/watch?v=WNIoB9mK7Hg[/QUOTE]



Just wondering who changed the trans fluid? If it was professionally done they should have the correct amount. If I recall you were having this issue, and then decided to do the fluid change correct?


To check the vehicle should be idling in park. Pull the dipstick and wipe it down. Then re insert the dipstick the fluid should fall with in the hatched area range. If its low say to the bottom end of the hatched area it should only need one pint.


I don't think throwing inexpensive parts at a possibly major problem to try first is throwing money away. So long as if it turns out the rebuild is necessary those parts can be reused. Trying the cheapest solution to a problem with many possible paths is prudent.

 

[DangerGirl]

I did the fluid change, did not flush, have been told by too many of their horror stories and decided a change would probably be fine.

I know how to read the dipstick and know how to check the fluid, I was just wondering if there is something I am missing since it seems to be hard to get the level exactly right. Maybe I am over thinking it but I just do not want to put too much in.

---------- Post added at 06:42 PM ---------- Previous post was at 06:39 PM ----------

Video of the truck in action.....

http://www.youtube.com/watch?v=WNIoB9mK7Hg

 

[Gordy]

I did the fluid change, did not flush, have been told by too many of their horror stories and decided a change would probably be fine.

I know how to read the dipstick and know how to check the fluid, I was just wondering if there is something I am missing since it seems to be hard to get the level exactly right. Maybe I am over thinking it but I just do not want to put too much in.

---------- Post added at 06:42 PM ---------- Previous post was at 06:39 PM ----------

Video of the truck in action.....

http://www.youtube.com/watch?v=WNIoB9mK7Hg

So long as it falls in thge full range you are fine.

 

[Jay]

The video does help clear things up. It's an 04, not an 05 like said earlier... 70mph, 3.73s (04-older 4wds), 30.6" tires (16" wheels), and 3rd gear corresponds to ~2900rpm. Video shows this is accurate. 65mph and 3500rpm doesn't happen in any gear with this arrangement so throw out my earlier assessment about not shifting into 3rd.

You are getting both the 1-2 and 2-3 shift, which is good. Both solenoids are good and the spool valves are moving freely. Since the shifts were firm i HIGHLY doubt you will need a rebuild. Both the band and direct clutch are working fine. the difference in 3rd and 4th gear is just the band applies.

The next easiest thing to check will be to pull the servo cover off (passenger side of trans) and check the seals on the 4th apply servo (it's the one that sits in the cover). If these leak then 4th won't apply. You will need to order a new o-ring kit to replace the cover... it's your call on this next suggestion... while you're in there I would replace all the o-rings on both servos. If you ever wanted to install a corvette servo this would be the perfect time to do it.

If that doesn't fix it then the valve body will have to come down. The plastic 4th accumulator piston is most likely cracked and leaking a lot of fluid, preventing the band from applying (it may be slightly applying, but just enough that you don't notice the slip). In other words, I wouldn't drive it in D, just 3 since you don't want the band to burn which WILL need a teardown. The bore for the 4th accumulator piston is behind the separator plate, inside the case housing. Replace it with the factory-style aluminum piston or sonnax pinless (FWIW I block off this accumulator by hammering in a checkball into the feed hold in the case... firms up the 3-4 shift only slightly and removes a potential leak source for good).

If you go through all that trouble, I would also recommend you or a trans guy install aluminum pistons in place of the factory plastic pistons in the forward, 2nd, and 4th accumulators while you're in there (you can block 4th like said earlier with no ill effects). Get a new separator plate from a GM dealer as the metal check balls have beat it up good by now... speaking of which, throw away the metal check balls and replace them with equal size (0.25") Torlon check balls (get them at a Ford dealer). The torlon balls are lighter, seal better, and won't beat through the separator plate after 100k miles and kill the transmission. Put a new boost valve in it too (I like the sonnax .490")

Edit: also, if you pull both servos out you will see a little checkball capsule in the case. Buy a new one of these and replace it if/when the valvebody comes down. This checkball is known to leak, and when it does it almost instantly burns up the direct clutch.

Pretty much everything i discussed here can be had for under $200 if you shop around and could easily get your trans to 200k+ miles. I've had many of my work trucks go to 250k+ on the original trans with the things i listed here (which were all done at around 100k miles). The situation with accumulator pistons, separator plate/checkballs, and the boost valve are what normally kill a 4L60E with miles. It's these things damn near every time.

Sorry for the length, hope this helps.

 

[DangerGirl]

Finally Fixed....

Well, I finally took it to a transmission shop and $1300 later it is fixed. I had them update all the things Jay suggested to update and they rebuilt the transmission. It had worn belts, the two/four clutch was burnt and one of the clutches had teeth that were worn and the drum (I believe that is what they said) was burnt. All in all it was in bad shape but now shifts and drives great.

Thanks to everyone for your help. It was MUCH appreciated!!

 

[Jay]

Glad to hear you got it fixed.

Just so you know, the band IS the "2/4 clutch" (there's only one band in a 4L60E and it only works in 2nd and 4th gears). The clutch that had "worn teeth" sounds like they are talking about the forward sprag, which holds in 1st, 2nd, and 3rd gears. Remember, 1st gear is just the lo/rev clutch applied (sprag locked), 2nd is the band applied (sprag locked), 3rd is just the direct clutch applied (sprag locked), and 4th is both the direct clutch and band applied (sprag freewheeling). The workings of a 4L60E is quite simple, it's the hydraulics that make this trans hard to build correctly since there are many overlapping circuits. The checkballs are the only things keeping this trans from locking up.

After watching the video and hearing the band being burned (which also warps the reverse input drum it acts on), I'm pretty sure that either the 4th accumulator was cracked or the 4th servo piston was leaking, causing the band to ride the drum like I said earlier. It was trying to engage OD but couldn't get enough force on the band to hold the rev input drum (and hence, the sunshell) still to engage OD. What was happening was while you were still in 3rd gear, the band was loosely applying the RI drum and just burning it to bits. The best thing you can do if OD is not engaging in a 4L60E, is to drive in "3" so the band won't try to apply. If you have 2nd and 3rd, there's no reason to not have 4th unless the band is slipping furiously.