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1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 1:42am
by Regnent
Hello,

First off, I read a few of the posts similar (or exactly) like my issue. I'm looking for clarification on a couple points.

I just got a 1997 Astro Van 4.3, which I assume uses the 4L60E transmission.
270k KM

It's been driving fine, but there was a delay in shifting when 1st started. Reverse was incredibly sluggish, even weak untill it had been driven a short time. (-15/-20C) After that, shifting from park to drive or reverse was 'normal'.

I was in a hurry when I checked my Transmission fluid, and ended up checking while it was not running, and it appeared to not be empty. (was up past the hatching)

We were going to the city doing 110 KM, slowed to 80 for a town, then upto 120 for primary highway speeds.

About 2-3KM later, I head the engine 'whine', and acceleration was lost.

After I pulled over, I check the fuild, it was low (about 2 litres low, so LOW), air filter, etc whatever was easily checkable for no power. I filled it to the proper levels while running after limping back to the town. (No change after)

I found that as soon as I hit about 60 under normal acceleration, the 'whine' returned, and power was lost.
It varied from 35-60 wether I had power or not, and going into 2nd had no issues.

Now I've read that this can be many things, from a solonoid (2-3?) to possibly a clutch?, wiring or just a wonky computer.

I pulled both fuses for the ECM and left it a good 10 minutes, although I read that pulling the cables does the same thing? (Assuming that pulling the fuses works in the 1st place)

I redrove it in town and nothing had changed, Drive and 3 both function up untill it wants to go into 3rd (I assume) around 40-60 depending on how hard I accelerate.
When I give it more thottle (normally when I give heavy throttle it shifts into some other gear, passing? OD?) it is still 'whining', although there is some power. I assume that it is shifting into the passing gear (or something), OR it is slipping and just the higher RPM is resulting in some power. (the power is 'weak', the engine is still whining, and I did not want to push it by giving more throttle to see if it is just the passing/od gear being weak due to only going 60ish km/h)


By whining, it basically sounds like it's not in gear at all.

So what I'm looking for is clarification to some things I would like to check, as I have to goto my works shop to tinker.

  • If I drop the pan, do I need to drain any fluid first? (I'd think so?)
  • If I'm checking for debrise what is considered normal or not? (Obviously anything metal, shavings, pieces, chunks, larger 'stuff' is bad)
  • If I'm to check the soloniod is there a way to test it? (Can I swap soloniods to see how that affects it?)
  • Is there any way to check the wiring for the soloniod? (out side of visual)
  • My Haynes Manual has no mention of soloniods (anything internal is skipped), but does mention a TV Cable. Could this be the cuplrit?
  • Is there a good 2L variance between running and not while checking tranny fluid? (And yes, I know, bad. I should have spent the time doing it right the 1st time!)
Any other general observations or suggestions on things to check or test while I've got it at the shop?

I'm REALLY hopping this isn't a done transmission.

Thanks!


PS! I've got no check engine light (I can't find one on the dash), so I have no idea if there's any codes or not. :(

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 5:14am
by Matrixx
Hi Regnent

Welcome to the Forum.

Yes you have the 4L60E Transmission.

If your stomping on it all day long with that many miles on that transmission, then I can assure you, you will have it punched out in no time flat. From what I'm gathering here, is it is shifting fine through the gears, it's just giving off a whining sound, is this correct? This "shouldn't" be a solenoid problem if you're not getting the classic hard shift that comes with a bad solenoid.

The fluid does need to be checked properly. 2 quarts low at that those speeds can affect the performance of the transmission.
Link: viewtopic.php?f=70&t=2530

At this point I would have a look at the inside of it yes. Get the transmission filter kit and the correct transmission fluid which is at the link above. A metallic "dusting" or "fine film" at the bottom of the pan is normal wear and tear, anything larger than that is reason to take notice.

An improperly adjusted, worn, or stiff cable can and will give these symptoms. Make sure the shift linkage is on correctly as well, if it's reversed, it will act exactly as you mentioned. I reversed my linkage on my engine re & re (tired) and the sounds it gave off were Gawd awful and very sluggish in shifting as well. Once I found the problem and fixed it everything has been fine since.

You can check this with a helper in the drivers seat shifting gears while your checking (underneath) to make sure each "detent" is being reached with the NSS switch (Neutral Safety Switch). It should "click" in each gear selected and their shouldn't be "any" binding or stiffness with the shift cable when moving.

Hope this helps, please keep us updated, Thanks.:)

PS: I would also recommend using WD40 on the cable and wiring in that area, it's exposed to the elements and corrosion can make thing s "bind" (cable) or "short" (wiring). Just a heads up on that.:)

PSS: Hmm, another of the wall possibility is a binding starter that doesn't disengage properly, have a listen to that when your under their as well.:)

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 6:13am
by Regnent
Shifting once it was warmed up was 100% fine, the slow engaging when cold may have been due to low transmission fluid.

And 3rd is simply missing. It accelerates and shifts 'perfect' (barely noticable) till it wants to hit 3rd, then you loose all power (like letting off the gas, but with the engine whining) and the engine sounds like it's just revving out of gear.

It was working fine beforehand, and I had not done any work.

I can't hear anything out of place, but I'm going to take a closer look at it in the morning at the shop.

It's going to a mechanic for a provincial safety Tuesday, and I'll probably ask them to check for codes before they do work on it.

I also 'learned' to stop stomping on the gas driving a '84 dodge b350 with a pissy 360. It's amazing how you learn to drive with more patience when your auto guzzles fuel if you try to drive like a race car. ;)

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 11:40am
by Matrixx
Hi Regnent

Hmm, ok that clears things up, thanks. I re-read both posts and see now what your asking about. What does the transmission fluid look like? Loosing 3rd gear isn't a good sign at all, no. I'm a bit surprised you don't have any codes showing (SES Light on).

The computer should have put the the transmission in "Limp Mode" to protect itself. I'll have a closer look and if I come up with something not already posted, I'll let you know.

Check what has been mentioned anyways.

I'm sure others will chime in if they can.:)

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 12:15pm
by tnhillbilly
Hi, I saw in your first post that you can't find a check engine light. It is in the instrument cluster. It should come on when you turn the key on before you start the van. If it does not come on when you turn it on the bulb may be blown or someone could have removed it. If you have the owner manual it will show you exactly where it should be. I have a 96 and if memory serves me right it is on the right side. Sorry to hear about your tranny problems. I do know that these trannys have a bore in the valve body that is bad to wear and the seperator plate is also bad to wear where the steel balls are. I don't know if either of these would cause you to lose 3rd or not. It will take someone with more tranny knowledge than me to tell you that. I hope you luck and keep us updated.

P.S. You asked about draining the fluid prior to dropping the pan. Unless someone has installed a drain in the pan you will have to loosen the bolts on the pan and let it run out 1 corner of it. You will also more than likely make a mess and take a fluid bath. :x

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 12:25pm
by Matrixx
Hi Regnent

Pull the transmission fuse located under the dash up on the firewall just to the left of the brake pedal. It's a 10 amp fuse marked trans in slot #20.

This should default to 3rd gear (make sure it's 3rd and not 2nd) and you will know what area the problem is (electrical or mechanical). Please keep us updated,Thanks.:)

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 7:41pm
by Regnent
Well, I've had the thing scanned, and no codes were given.

One transmission shop said that bascially anything electrical should trigger -something-.

Both thought that it could be the 3-4 clutch. Both said with the milage it might also just be time to replace the tranny.
The second one said that 3rd and OD were really sensitive to low oil.

I also mentioned to the 2nd one because it occured to me;
I noticed when I drove home with it (when I got it), there was an odd vibration and noice, very similar to the difference when you go from ashphalt to concrete (noticable, but not 'scarey') that was very intermitent and random. Didn't matter if I was going 90 or 120, it would come and go. Sometimes it would be for a few moments, othertimes it would remain for a period. Overall, I'd say that it was present 50-70% of the time. Acceleration didn't matter, turning didn't matter. (I tried to shift the weight on the suspension from left to right by moderate 'weaving') It just came and went, and was only present (or noticable) when going highway speeds. It could have been present at lowe speeds or other gears, but I didn't notice it.

He did say it could have been the transmission slipping.

Although, I did notice that it was doing around 14-15 MPG highway (300km, 45 or so litres), and it's rated for 20 on the highway.
Temp was about -15, the grade was prairie, so alot of flat, and some hills.

Since the comp didn't return any errors, I would assume emissions and such are normal, the air filter was descent, so mileage shouldn't be that far off.

If 3rd was slipping as much as I think it may have been, that could very well tie into a 25% loss of fuel economy? My logic tells me very possibly Is it normal for a gear to slip that much and still do 200km city driving, a 700km trip, plus 3 150ish trips to the city?
I -think- the vibration was getting worse (longer, more consistant) than when I first started driving it.


Now, both tranny guys I talked to seemed pretty adiment that it was not the soloniod (too easy a fix?), the one my dad talked to (and does business with) figured it very well could be, due to it being a common problem.

Now, I don't have a clue how the solonoids work, can they have partial failure? Can they fail slowly?

Worst case at this point is to replace it, considering it's a very cheap fix vs a refurbed or even used tranny, so the potential wasted money far outweighs the potential cost of a new/refurbed/used tranny far as I'm concerned.

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 9th 2009, 7:43pm
by Regnent
Oh, and yes, we (the mechanic and I) found my engine light ;) Tucked way down on the panel, usually blocked by the steering wheel. ;) It was not on durring or after the problem (or prior)

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 10th 2009, 7:34pm
by gtkane
The torque converter is pooched. No power=no torque multiplication.
This would also explain delay in reverse when cold(converter drainback)

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 10th 2009, 9:47pm
by Regnent
That would affect a single gear? The mechanic also mentioned that it could be that.

Is that repairable? As in DIY? Or is it pretty much a replacement?

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 11th 2009, 2:31am
by gtkane
It probably is affecting all gears, but is only noticable in third because of a gear ratio of 1:1.

You could DIY, but chances are the trans would be due for a rebuild anyway...

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 13th 2009, 1:25am
by Regnent
Ok, update;

I dropped the pan, and I -think- I swapped the solenoids (I'm not gonna make a bet)
Fluid was in rough shape.
I found a -very- small amount of fillings and bits, all smaller than 1 mil pretty much, kinda like sand grain size, and maybe enough to be a 'pinch' worth.

Fair amount of 'sludge'.

I filtered and kept the filter rag for the old stuff, and wipped out the pan, keeping the wipe rag.
Topped up with 4L of trans oil.

Acting the exact same way, so either the small amount of filings is due to a mechanical failure, or maybe the harness is fubared.

The only time the B solenoid turns 'off' is while in 3rd and 4th.

Since I'm not the one paying for a new tranny, I suspect I'm going to be requested to just replace the solenoids.

Regardless, I think I'll be making a trip to a tranny shop with rags in tow.

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 13th 2009, 1:56am
by Gary
Make sure the tranny shop flushes the t/c too.

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 13th 2009, 10:41am
by Matrixx
HI Regnent

Ok, from what I have gathered here is you do in fact have filings of some kind in the pan. My suggestion at this point with what you have just said, the mileage on the transmission and the shape of the oil (with sludge in it), is to save yourself some money by putting new parts in an old (worn) transmission and replace it with another used or reman. one.

Please keep us updated,Thanks.:)

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 14th 2009, 4:56am
by Regnent
Ok, solenoids replaced, new filter, and problem persists :(

Ripped apart old filter, and there's about a 1tsp -1tbs of what looks like charcoal bits (think uhm, 1-3mm sized bits).

I'm thinking clutch, since it isn't metal per say, but 'burnt' charcoal.

bleh!

Re: 1997 Astro 4.3 3rd gear problems

PostPosted: March 14th 2009, 11:16am
by Matrixx
Their shouldn't be anything in the pan like that at all Regnent. Yes It does appear like a clutch band is flying apart from what you have just mentioned. Get a second opinion on it if you can. Please keep us updated, Thanks.:)