Trabant Tech Forum

Here is my experience with SAE-30 engine oil and White Shepherd stop leak.

Initially the stop leak didn't seem to the fix the oil leaking from the passenger side CV joint. But after three weeks it finally swelled the seal up and stopped leaking totally. Before it was making a nasty mess on my garage floor but did not seem to be slinging it out when driving.

The coldest I've driven my Trabbi so far is at 23F. The engine struggled a bit to turn over at this temperature but eventually fired up. I suspect new battery terminals might help this.

I do know at this temperature the amount of smoke mixed with condensation is quite dramatic!

So far no grinding, shifting feels just the same as with the "red stuff" that was leaking out of the CV joint and the freewheel device still functions.

As I have mentioned before Fiat gearboxes love thick oil. GL-1 90 weight. 20W50 engine oil caused 3rd gear to grind when upshifting on my Yugo. I went back to GL-1 90 and no more grinds.

I wonder if GL-1 would be too thick to use in a Trabant transmission? If you had a transmission with worn syncros if this would buy time.

OK, I hit 25,000km with Comrade Trabi, a few weeks ago (now I'm at 27,000km) and did the dreaded 5,000km service.

Draining the transmission fluid went exactly as I predicted earlier:
It was dirty, but not as dirty as last time!
So, it looks like my hypothesis #1 (above) is correct, that the Dexron3 auto trans fluid is slowly clearing out decades of accumulated crud.
Naturally, I refilled it with more of the same: Valvoline Dexron 3 ATF.

The shift quality remains better than the HLP, shifts are easier and so far, after 11,000km on Dexron3, no noise or other signs of catastrophic damage.

Alas, my freewheel is still resolutely stuck!

11,000 kilometers or 6,800 miles on the "wrong" fluid and things are still working better than ever.

Just keep this in mind:

1-The effect on a normally functioning Trabant freewheel is unknown, though ATF is specifically formulated for freewheel-equipped automatic transmissions.

2-I am a full-time car mechanic who is prepared to repair any damage I may cause by experimenting with fluid types.
Are you?

Now at 29,000km with comrade Trabi and thought I'd change the transmission oil again....
This time the Dexron3 came out pretty clean!

So my hypothesis #1 appears correct.

After 13,000km on Valvoline Dexron3 Automatic Transmission fluid, the transmission is shifting great, the leakage is down, there is no apparent catastrophic damage and the clean fluid indicates a low rate of wear.

And as always, the freewheel remains stuck. I'm going to disassemble this sometime to see if it is actually welded or pinned together.

How does the freewheel look like, and how does it work?
I am not going to take my own gearbox apart, just to check that.

A freewheel is usually composed of rollers like a bearing has or toggles which are like strangely-shaped rollers.
The rollers are positioned between two races, like a bearing.
Usually the inner race is specially formed so that when turned one direction the rollers are forced outward thus locking them to the outer race.
When turned the other direction, pressure is released and the inner and outer races are disconnected and free to rotate relative to each other.

Practically every automatic shifting gearbox has at least one freewheel device and usually at least two.

Thanks, i guess yours is welded solid then, thats what i would do if i had to block it. I have seen one do it on the diff of a BMW to drift it.
Can you get a freewhell as a loose sparepart? or do you need a complete gearbox?

The freewheel iteslf is readily available.

If someone welded it together, 4th gear and/or the shaft would probably be needed as well.
Those don't seem to be as available.

I guess my free wheel has seized up.
When i had the gearbox out, i turned the input in one direction, and the output did not move, but the output did turn when i turned the input the other way.
But today we had to get te car weighed (something about the tax), and my mom drove it for her first time, and she went from 3. to 2. because she was not used the the gearchange, and it did not freewheel, so when i got home i put it in 1. gear, and pushed the car forward, and the engine also turned, and it also does when i push it backwards.

Does this mean i have to be careful at long downhill? maybe pressing the cluch, and use the brakes?

The freewheel in a Trabant transmission only operates in 4th gear.

Gears 1,2,3 and reverse have no freewheel function.

The idea is to prevent oil starvation during periods of extended high rpm and closed throttle, as when descending a large hill or mountain.

Short periods of deceleration are OK.

Then it works, i just put the car in 4. and it only rolls forward.

Hey Keri, I didn't see you comment on my freewheel device question. When you say your freewheel device is "seized" does that mean you have no fourth gear or it means 4th gear won't disengage when you take your foot off the accelerator?

I don't know if you read my post or not. I figured you might comment on it.

I had been using SAE30 for awhile and had no issues with the freewheel device even in subfreezing weather but then all of a sudden the other day mine would not "catch". I would put it into 4th gear and it was as if I had no fourth gear! I could go back to 3rd them to 4th and then it would catch.

After awhile it seemed to do better but there was still some delay action going on. Sometimes I'd feel a loud "clunk" when it did catch. It seemed to be worse at higher RPMs.

I put some Dextron III in mine like you did and saw an immediete improvement. No grinding in gears or easier shifting but the freewheel device seems to catch much quicker and sometimes I don't even feel it catch when press the accelerator in 4th. Used to it seemed it would take about a second before 4th would catch.

The only major difference I can tell is the transmission sounds noisier but I suspect the thick gear oil was dampening some of the noisy worn bearings.

Another difference is I went to a car show the other day and after I got home, did the math and got 33 mpg! The most I had ever gotten was 25 mpg. But when I got 25 mph I was on flat land holding speeds of 55 mph and seldom at full throttle. When I went to the car show I had to go up a lot of hills and drove the car more agreessivley at times.

Would the thicker gear oil cause that much resistance in the drivetrain?

I do have concerns about running AFT in a manual gearbox especially with the bearings but automatics have bearings.

I know not to use GL-5 because it contains sulfur. That's a no-no in Fiat gearboxes.

Been Busy! Went to DC in a bus, been to all kinds of events, meetings and whatnot.

There is nothing in a Trabi gearbox that would need the thicker oil.
It also does not have Hypoid gears, which would need the sulfurous Extreme Pressure additives.
I now have 35,000km on Comrade Trabi, most of it on ATF.

My freewheel is stuck. This means 4th gear works but does not freewheel when coasting in 4th.
As I suspected, your experience seems to indicate that ATF is probably one of the best lubricants for the freewheel.
This makes sense, as virtually all automatic transmissions have at least a couple of freewheels.

And yes, the additional friction cause by a thicker lubricant will reduce gas mileage. Viscous Drag matters, especially when you have only 26hp.
The low power loading is another reason thick oil is un-necessary.
That is why some carmakers switched to ATF in manual transaxles back in the '80s.
Transaxles that were suspiciously similar to Trabant ones, but with triple or quadruple the horsepower.

OK, The Long-Awaited Long Term Results are in!

What Long-Term results?

Why, the What Happens When I Put ATF In A Trabant Transmission Results!

I now have 36,000 kilometers on Comrade Trabi, 20,000 of which are with Valvoline Dextron 3 Automatic Transmission Fluid.
I emphatically do NOT "baby" this car or treat it particularly gently.... just ask Bountyflier!
As such, I feel moderately qualified to offer some opinions on some of the decisions I have made. Like switching to ATF!

The Results:

Seal Leaks:
The AFT made no major effects, maybe a slight reduction is leakage..
I replaced the leaking input shaft seal some time ago and the leaking RH side output shaft seal last week.

Shift Quality:
The transmission shifts very much better than it did originally or with the correct LDM-supplied HLP-68 fluid.
It was previously bad enough that I was considering replacing the synchronizers, now I don't need to.

Shift Ease:
The transmission shift effort is much reduced over the original fluid. Especially on cold days.

Fluid Cleanliness:
The original fluid was incredibly dirty. The correct HLP-68 fluid ran 16,000km and stayed clean.
When I switched to ATF, I started changing the fluid at 5,000km intervals to record the results.
The first two changes of ATF came out incredibly dirty due to the high level of detergent in ATF.
The 3rd change came out much cleaner and the 4th, after 6,000km, came out perfectly clean.
As I theorized it might, the detergents in ATF cleaned out the years of accumulated crud until the crud ran out.

Effect Upon Freewheel:
Comrade Trabi's Freewheel has been stuck since the day we became acquainted. Nothing I have done in the last 36,000km has had any effect whatsoever.
My speculation is that someone once disassembled the transmission and welded the freewheel together to stop it from slipping.
Happily, Turbofiat124 has recorded a beneficial effect ATF had on his Trabant's freewheel.


So, I hereby pronounce Automatic Transmission Fluid as relatively safe for use in Trabant transmissions!

Good to know. My Trabbi's freewheel device seems to like ATF fluid much better than SAE30. Although the oil seemed like it was dampening worn bearings.

More long-term results of Dexron 3 Automatic Transmission Fluid:

1 May 2012, "0km": Date of Comrade Trabi's start of active duty in Chicago

9 May 2012, 100km: Date of Comrade Trabi's first transmission oil change with LDM supplied HLP-68, Incorrect original oil was very dirty.

?? Jul? 2012, 6,000km: Date of Comrade Trabi's 2nd drain of LDM supplied HLP-68. Came out moderately dirty.

12 Nov 2012, 16,000km: Date of Comrade Trabi's first transmission oil change with Valvoline Dexron 3 ATF. The HLP-68 fluid came out clean. Significant improvement in shift quality noted

10 Jan 2013, 21,000km: Date of Comrade Trabi's first drain of ATF, came out extremely dirty.

1 May 2013, 25,000km: Date of Comrade Trabi's 2nd drain of ATF, came out less dirty.

9 July 2013, 29,000km: Date of Comrade Trabi's 3rd drain of ATF, came out pretty clean. Noted further improvement in shift quality.

15 Sep 2013, 36,000km: Date of Comrade Trabi's 4th drain of ATF, came out very clean.

?? Dec 2013, 40,000km: Date of Comrade Trabi's 5th drain of ATF, came out very clean

?? May 2014, 45,000km: Date of Comrade Trabi's 6th drain of ATF, came out very clean. Noted leakage rate of less than .1L/5,000km.


Today's date: 29 June 2014, 47,500km total.
31,000km with Dexron 3 ATF in the transaxle.
Comrade Trabi is still shifting great! The transaxle exhibits no sign of poor lubrication or unusual noise.

At various points, the input shaft and RH output shaft seals were replaced.