86.5 Auto drops in neutral in every corner (Page 1/4)
Cliff Pennock APR 11, 06:41 AM
So my Fiero started doing this over a year ago but only in very tight corners. I've had this before and it was always due to low tranny fluid levels. But when I checked the fluid, it didn't seem low at all. And since I didn't drive the car all that often, I actually forgot about it. But in the past 6 months or so, I've driven my Fiero almost daily and the dropping in neutral has become progressively worse to the point that it does it now in every corner, except at high speed (50mph+).

If I check the level, it's incredibly difficult to see if it's full or empty. The dip stick does get fluid on it, but it's really hard to tell what the level is since there's not a very clear line where the stick is clean and where the stick has fluid. The fluid itself is clear, like new.

So what to do? Just drop in half a quart or so and see if I see any change on the dip stick? Or is the fact it drops to neutral a 100% sure sign it's low on transmission fluid?
RCR APR 11, 11:16 AM
Hi Cliff..
Does it start slipping or drop into Neutral? If it's slipping, it could be fluid level, but unless you have a leak, where is it going? When was the last time the filter was changed?

If it's shifting into Neutral, I was thinking something is moving in relation to the shifter/cable. Broken mount or something?

Sorry, probably stating the obvious...

Bob
Cliff Pennock APR 11, 11:49 AM
I'm guessing it's slipping (how can you tell the difference?).

As far as I know, the filter has never been changed. Unless it was changed when my engine was rebuilt some 20 years ago. Either way, my understanding is that it's better to leave the filter alone when it hasn't been changed for such a long time.
RWDPLZ APR 11, 12:28 PM
If you can't read the dipstick, it's probably low, if you're not sure a good mechanic should be able to tell. Trans cooler lines running to the radiator under the driver's side of the car may be leaking, or the cooler in the radiator itself may be leaking, it's going somewhere, see if they're wet. If you disconnect a cooler line hose at the transmission and put it into a bucket and turn the car on for 5-10 seconds, you should get a lot of fluid to come out. When the movers damaged my car and ripped the cooling line off loading it onto the trailer, there was fluid EVERYWHERE after a few seconds.

Do you guys have Lucas products over there? They make an additive that works great. My car would slip going up inclines when the lines started to rust out, this fixed it, still working fine 10+ years later.

https://www.amazon.com/Luca...Fix-oz/dp/B000ARTZPO
cebix APR 11, 12:32 PM
As for checking the level, it's kind of annoying really. I do it this way.

Got to get the trans hot, drive some miles (manual says at least 15 highway) but don't check the level immediately after a highway drive as I find the fluid will foam. Drive now slowly around town (but not in traffic, don't "lug" the motor, don't drive heavily) for some minutes before parking at a flat surface and shifting through all gears and park again. Remember keep the engine running.

As for actual level on the dipstick if a flashlight won't help I wipe it down with a white paper towel until I see it gets wet, that's my level. Gotta do it slowly cause the paper towel will soak up that fluid quickly.
Dennis LaGrua APR 11, 12:36 PM
As long as you do not do a complete fluid flush. I see no negative effects in changing the trans filter and putting in some new fluid. If it was never changed it could be restricting fluid flow. As for checking the level it needs to be done with the engine warm. The fluid should have a red tint to it. Ifs it brown it is burned.
While you could have transmission problems, I have worked on cars where a new filter and some fluid cured the issue. Changing the filter is an easy and relatively inexpensive job. IMO, worth a try.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

skywurz APR 11, 01:26 PM
Mysteriously disappearing Coolant and now Trans fluid.... This makes me suspect of that radiator.

Edit:

[This message has been edited by skywurz (edited 04-11-2021).]

Cliff Pennock APR 11, 04:20 PM

quote
Originally posted by skywurz:

Edit:




😂

Anyways, I can't think of a way that both the trans fluid cooler and the radiator itself would share a problem causing them both to loose fluid. If the trans fluid cooler was leaking, wouldn't trans fluid leak in the coolant and vice versa?
theogre APR 12, 01:15 AM
Very likely AT has low oil.
You check AT oil level w/ AT Hot in Park and Engine Running.
But when AT "drops out of gear" need to add some just to drive so AT heats up. Add only 1 Pint or 0.5L (.473176) max to hopefully stop this, then drive then add more as needed.

AT Stick often has 2 holes at ~ full and add mark. One near Add should always see oil unless you need oil.

If can't read the stick...
Pull out, spray w/ carb, brake cleaner or even 70% or higher alcohol, use a Sharpie type marker & "paint" full mark to tip of the part.
Install, wait a few sec to a minute, them pull. AT Oil can wash away marker marks showing level. Micro Grams of Dry "Sharpie" won't be notice to the trans.

Red Color Can Fade over time. Brown Color isn't always "Burn oil" just dirty oil. "Burn Oil" Smell Burned as oil and friction parts burns, Dirty oil smell mostly same as new oil.

AT "Cooler" leaking in the Rad would push Coolant IN TO the Trans and "Destroy" the Trans.
Because AT "Cooler" line has Near 0 PSI. Oil is "Waste" Oil return from Main pump and regulator and dump into the sump/pan.
While Coolant system operates up to ~ 15 PSI.

AT "Cooler" lines and other areas can weep oil for weeks to months and never put a lot of oil on the "ground" while parking.
⚠️ Warning: If AT Rubber hoses are iffy, Replacement hoses must be rated for this job. Vacuum, Heater and Fuel hoses will not work.

Replacing Dirty Oil often won't cause problems but many replace oil on a dying trans and new oils may wash away crap holding it together.
Sim to BS saying Syn Engine Oil cause Engine Leaks and/or burning oil.
See my Cave, Automatic

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Blacktree APR 12, 11:16 AM
So the transmission oil filter hasn't been changed in 20 years? YIKES! It's probably clogged. That would explain the bad behavior (i.e. low line pressure).

I would suggest doing a fluid and filter change, and re-evaluate.