Odmark

Was hitting the town this saturday in the -73 custom cruiser, and im not gonna lie, some dragracing occured.
Sunday morning i was going to the store, and reversed out of the driveway.

When i put it in drive it took a while before it engaged (is that the right way to say it). Didnt think about it much just drove off, and when i picked upp som speed the gearbox started to whine, almost sounded like a supercharger. It only occures when i push the gas.

It shifts fine and when it gets warm the whining almost goes away. Still there but a lot less loud. Still when you give it a lot of gas though its pretty loud.

Any ideas? Hoping i dont have to rebuild since no one around my town does that.

oldcutlass

Check your fluid level in park, on flat level surface, after it completely warmed up and with engine running. Also look for any odd smell and discoloration in the fluid.

rocketraider

1st thing comes to mind is low fluid level causing pump cavitation or "whine". It's possible under hard use some fluid blew out the vent tube on top of the trans.

Check the power steering pump too. Low PS fluid level will cause the PS pump to whine.

Drag racing a 5200 lb wagon- I love it!

garry442

I had that happen once in a '68 Vista Cruiser.A simple filter change fixed it.

droldsmorland

The most common causes of a whine in a TH400 is generally caused by
1. Low fluid level causing pump cavitation.
2. The Oring on the filter is rolled or broken causing the pump to suck air
3. Pump restriction....clogged filter, cooling line restriction etc...
4. Pump gears on their way out
5. Bad torrington bearing
6. Bad Sprag
etc etc...sometimes its as simple as fluid level or a filter change sometimes it broken hard parts.
Step one read the pressures. The pressures are the quickest way to evaluate an automatics health.

MDchanic

Step One: Make sure it's full.

- Eric

Odmark

Low fluid was the problem. I always thought you should go trough all the gears a couple of times before checking the fluid, and i did that earlier and the level looked okay, but when i checked in park now it was way too low.

Filled it up now and works like a charm, thank you all

rocketraider: Its actually pretty fast, installed a HEI distributor as well and the engine got completley different characteristics.
Put some newer turbo cars in their place, people where pretty amazed haha.

oldcutlass

Good to hear.

Lady72nRob71

I wish you had some googley-eyed pictures of some of the ones you beat with the beast!
Glad it was an easy fix.

Odmark

Well that was a short lived victory, the wining came back last night. Checked the fluid level and it was below "ADD" once again (I got it warmed up properly). Have not noticed any leaks at all but i drove the car home and parked it.

Today i went to get some oil, the only car i had avalible was the olds so i had no choice but to take it. It was slow to engage reverse and drive as before, and i thought it didnt pull away normally, felt as it slipped a lot. So i stopped for a fluid check, was above add but i decided to go home since it wasnt driving properly.

And now the whining was gone Engages gears normally and pulls perfectly. Took it for a drive to warm it up and checked the fluid level again, it was perfect at the "FULL" mark. No strange smell from the fluid and no discoloration.

Anyway bought some oil and started my journey home, and there it is again! And this time it whines when im in park as well, not as loud but still loud enough to hear it.
The car still shifts perfectly and engages gears as its supposed to.

What is this? Can pump failure cause this?

droldsmorland

Your pumps on its way out. Get it rebuilt before other parts suffer and the price goes up accordingly. It will eventually leave you stranded. TH400s are relatively cheap to rebuild.

Odmark

Was afraid of that. Spent hours looking for a new/used pump or rebuild parts, but seems very hard to find here in sweden.

oldcutlass

I would go to the next step and change the filter.

Odmark

I will try that first, the filter is only 170kr, about 25 bucks in us dollars. How much fluid goes in the trans? If i empty the converter as well?

matt69olds

Figure 5-6 quarts for a filter change. Your not going to be able to drain the converter, there isn't a drain plug. If its using lots of fluid with no visible leaks its probably sucking the fluid thru the vacuum modulator. It a small round canister on the passenger side of the trans. They are about 10 bucks here, I wouldn't have a clue what they would cost in Sweden.

While the pan is off, take a good look at the crap in the pan. Hopefully its just a little dust and grit, if its big chunks or LOTS of debris you have found your problem. Something is obviously wearing bad! Changing the filter is good preventive maintenance, but wont fix worn out parts.

jfb

do not use any tranny gunk for a quick fix either eventually the problems escalate with it.

droldsmorland

odmark check Jegs or Summit dot com. They have complete kits for DIY. They also sell the video with step by step procedure on rebuild as well as any needed updates. Be sure to purchase the bearing kit too as its separate. Its not too bad if you have moderate mechanical ability. An automatic is just a fancy hydraulic pump. Special tools needed are a large snap ring pliers, bearing race/installer tool, a puller to get the pump & drum assembly out. You can fab a puller with threaded rod and some steel. If you get friendly with your local trans rebuild shop even though foreign (to me) they will have tools and general knowledge to assist, treat them well if they do. You need to be very clean too. Flush out the cooling lines including the radiator cooler. Get a new torque converter. If your going in far enough to get at the pump your right there so do a complete rebuild. Drop in a shift improver kit too. Some things to keep in mind...be very careful with all the lip seals and nylon seals they can be damaged easily upon installation. One little nick and it will leak. Inspect the hard parts well and replace as needed. Make sure the stack up tolerance on the frictions/steels is right on spec. Clean everything including all the worm passages in the valve body.
The above mentioned companies also sell crate trannys too, dyno tested with a warranty.

oldcutlass

X2, before you disturb the pile/'s in the pan please take a couple of photos and post. If it's really ugly in there, then you can certainly do what droldsmorland suggests.

Odmark

Hello! Havent been online for a couple of days, lots of things going on.

Anyway, changed oil and filter today. There was a little goo in the pan but not much really, and pieces of the old oil filter wich was about half the size that it should be. Very hard to take pictures, you cant really see anything.

Dont think that the automatic oil filter had been replaced for a veeeery long time.

So far, no noise at all and everything works like a charm. Feels much better than before as well, much smoother shifts.
Hopefully problem solved, i have to drive it some more to be sure.

oldcutlass

Good to hear.

droldsmorland

Change the fluid at least two more times to get out any remaining old fluid. Or do a full fluid flush. Keep in mind today's Dextron isn't yesterdays. The manufactures have been able to back off on some/most of the lubricating constituents needed in an old school trans verses a new trans with a lock up converter. The lock ups don't generate as much heat. This allowed the makers to back off and of course save money on modifier compounds. I couldn't figure out why every time I changed fluid an old school trans with an unknown history it would chet the bed after 1-2K miles. One of our petroleum vendors enlightened me to the fact that the manufactures have backed off on certain modifiers that the old non-lock ups need. Hence you think your doing good and your not. Granted this was the era when lock-ups were starting to catch on so late 70s mid 80s. So Id imagine today's Dextron has even less of what a non-lock up trans needs. This equates to more heat generated which decreases component life. With the questionable internal condition of your trans I'd put the best fluid in I could find. It might get you many more miles until a rebuild is in order?
My suggestion is go with the higher end lubricants such as TCI, B&M, RedLine or Royal purple Schaffer etc...These are semi-synthetics or full synthetics. Find one compatible for an old school style trans. Call their tech line and ask. And or call a reputable (key word here) trans shop. or a racing trans specialist. A 400 can be built to live with today's fluids because the friction/disc assemblies and other internal parts have been updated to be chemically compatible. I now run TCIs clear race fluid. Have done so for 10 years now in both new & old transmissions.

Odmark

I was thinking two more times as well. Got Dextron II in it at the moment, dont know if its a proper oil but im not driving the car before i do the other oil changes anyway.
Is there a good way to empty the gearbox of oil? Last time i had to take down the pan and the oil went all over the place.

Seems like the previous owner changed the fluid, but not the filter, then put the pan back with the old gasket and a lot of universial gasket material. Cheap b*stards.

matt69olds

If your going to drain and refill the trans frequently then add a drain plug kit. Figure out where you want the plug and drill a small hole with the pan installed. It will take a while for the fluid to drain but will be sooooo much easier and cleaner! Once the fluid has drain out, remove the pan, change the filter install the drain plug kit and reassemble.

Odmark

I had to rebuild the trans after all, it stopped pulling forwards so i took it apart and the clutches were absoluteley fried!
I have a rather important question though, i did not wet the new clutches in oil before installing, because the guide i used did not tell me to do that. Do i have to take it apart again and wet the clutches or am i okay? (The trans is not installed in the car yet)
Very grateful for fast answer on this.

matt69olds

Technically, by the book you should soak them. As long as your putting the trans in and are absolutely sure you wont hammer on it until the engine has been run for a while I wouldn't worry about it. Run it thru the gears a few times, leave the wheels off the ground and free to turn and you will be fine. Leaving the wheels off the ground will minimize the load seen by the clutches until they have a chance to soak up some fluid. Make sure you blow out the trans cooler, you will be amazed at how much crap collects in them!

Odmark

Thank you, was a bit worried there

droldsmorland

The other reason for soaking your clutch packs is you get a more accurate stack up tolerance which is a critical spec. If the kit you ordered was an exact replacement kit you "should" be OK? Before you actually spin any wheels; with the car on the ground shift into all gears with foot on brake and at curb idle. Do this for about 3-5 minutes running up and down the gear selection. Then you can raise the rear and let the wheels spin. Do the same shift method mentioned above at still at idle. Once you have about 10 minutes of this at "idle procedure" on it bring it up to speed enough that it gets into 3rd. Keep it in drive and let it up shift into 3rd then back down to 1st. Do this several times. Recheck your fluid then road test. Contrary to what some say a trans has a break-in. So dont hammer on it until it has a couple 100 miles on it. What company or vendor did you use that did not mention soaking the frictions & disc pack prior to asm? I hope you used plenty of trans fluid on the bearing surfaces during assembly as well as petroleum jelly in various areas (optional)? If not reply Ill give you another procedure to attempt avoid catastrophic failure.