A cutaway view of a car final drive unit which contains the differential
A cutaway view of a car final drive unit which contains the differential

I watched the funny scene the other day. My neighbor minivan fell off the jack. It fell hard on its belly when the guy removed the flat tire. It could ended up very bad if somebody got hurt. Luckily just van’s belly had  couple of scratches and that was it.

So guess why it fell off the jack?

You guessed it right – the human error. Or I’d call it stupidity in this case. The owner of the minivan did not engage the parking break nor he ensured by any other means that the car would not roll.

The guy was changing one of the front tires of  front wheel drive Toyota Sienna. Once the flat tire was off the ground, lugs were  removed and he shook the tire the minivan rolled back a little bit, just enough to fell off the jack.

The lesson there for owner was that the differential lets one wheel roll freely once another wheel is off the ground even if transmission is in “P” (Park).

[image credit: wikipedia]

After a brief struggle with my parsimony, I have finally decided to buy original BMW transmission fluid. Sticker on side of gearbox was worn out, but it was of yellow color indicating that I needed MTF-LT-2 fluid. Local BMW dealer had it for MSRP price about $140 for 5 liters. It is a bit more expensive compared to everybody’s’ favorite Red Line MTL, which one could buy from for example OGRacing for just under $9 per liter.

The manual gearbox fluid change is really easy DIY project.

You will need the following tools:

  • 17 mm 6pt socket
  • Some ratchet
  • 17 mm box end or combination wrench, 6pt is the best in my opinion since plugs made from some very soft metal and you can very easily strip plug’s flange if using open ended wrench.
  • Torque wrench
  • Some hand pump
  • one or two feet of clear plastic tubing
  • Floor jack or similar to jack up the car

First of all you’ll need to jack the car up. I usually just drive rear wheels onto ramps and jack up front of car with floor jack, then secure jack stands. Some people drive front wheel onto ramps and jack up the rear. I personally find it a bit dangerous since car can roll away once rear wheel s are off the ground and besides my E39 has rubber jacking point in the front and nothing except rear differential on the back that I could use as jacking point.

Find transmission under the car after car is off the ground and leveled. Read the label and make sure you are going to use the right fluid for you gearbox. Here is view of transmission from under the car.

Photo from BMW325i.NET

Before you remove drain plug make sure that fill plug is not seized. And definitely use either sockets or box-end wrenches to break seize. I almost stripped my fill plug flange when tried to use open end of wrench. Believe me it is very soft.

Here is what color fluid came from my gearbox after 52000 miles. I seriously doubt that it is healthy to have it in the gearbox for the life of car. Well I have to agree with thought that the lifetime fluid is most likely BMW marketing gimmick to attract more customers. It is very unlikely that BMW cares what happens to our cars after 50000 mile warranty and they will gladly offer us replacement transmissions for one forth of car price.

Once plugs are removed and old fluid drained. Replace drain plugs and torque it, on my BMW E39 car it is to 70 Nm. Using hand pump and plastic tube pump transmission fluid into fill hole until it overfills and it starts to leak out of the fill hole. Replace fill plug, tighten it to same torque as drain plug (70 Nm). Check for leaks and you are done.

One more thing, do not forget to lower your car on the ground.

Is there any trick/technique/know-how regarding how to compress front strut spring with cheapo spring compressors like these ones, maybe location when you bite on the spring matter? I have all three of them know, borrowed and even bought last one. But I could not release the spring so it rests on lower rubber pad nicely.

strut spring compressor 1Strut spring compressor 2Strut spring compressor 3

My latest attempt last night looked almost as it should be. Just on one side rubber pad seamed a little bit off. And here is how it looked by this morning. Spring pushed rubber out completely on one side. So I have to compress spring again and try to realign everything. I just wonder what I was doing wrong since I can not get spring in place correctly.

I also wonder if compressors like the one below works on E46 since although they look similar BMW’s one shown in TIS. The one from TIS uses kind of ring adapter to press against upper plate. For some reason it seams like it should compress spring more evenly. Did anybody try such compressors?
BMW Spring Compressor fro TISHere is screenshot from TIS. The tool is shown assembled for E46 and upper adapter (it is the right one on the picture) is actually a ring. It does not look like anything from kit above could be used like that ring. And without such ring it would be worthless as any other cheap compressor just because there are not enough coils in spring