it's a matter of interpretation, not quality.

before, there were mineral oils and synthetic. synthetics were very expencive, so oil companys mad semi-synthetic oil.
but, somebody came to the idea to furter refine and purify mineral oil (hydrocracking), and they called it SYNTHETIC.
that's why you can buy 1 liter of synt oil for 4,5 pounds.

pure synthetic cost more and are far better then HC.
pure synthetics are not made directly from oil.
HC will never reach 0WXX quality.
HC require much more additives and so on.

so, don't trust everything you see, expecially if it comes from the one who sells it.

 

Fair enough. What I can tell you however is that

1. After changing my clutch I put in Comma Xtech 5W-30 and the box was not happy at all

2. I then went to a Castrol Maganatec 10W-40 which is claimed to be a semi synth and it was better but I was still not happy.

3. I then tried the FUCHs and the difference was impressive.

So in my experience whatever they have pur in there or have done with it certainly makes a difference.

Interestingly enough when I got the car the box was silky smooth with the exception of 3rd gear which was notchy changing up. Going through the service history I got with the car I noticed that when the gear box was changed SX75W-90 GL5 had been put in. Now when I drained it out it definitely had a copper hue to it indicating that the gear oil had been taking a toll on the synchros as expected, no doubt the reason for 3rd being the way it is.. When I drained out the 5W-30 the copper hue was still evident but at a much lower concentration no doubt this was due to residual 75W-90 that was no in solution with the 5W-30. Draining out the Magnatec had no evidence of copper whatsoever.

So the gear oil was by far the smoothest with the 5w-30 being the wors't. The Fuch's is pretty darn close to the 75W-90 but is notchy when cold which the gear oil was not.

As stated earlier I have now bought 3 lires of Redline MT-90. This is a GL4 spec gear oil specifically designed for use in manual transmission where either an engine oil or a GL1 - 4 gear oil is specified. It is a 75W-90 but in terms of viscosity Gear 75W-90 is the same as an engine 10W-40. So once I have done this I will report back my findings. I am however confident that it will not attack the synchro rings as I have read many other user reports on this oil and all are very favorable.

 

well, as much as I know about engine oils, gear oil info is really good and new for me.
so, I am very glad to talk somebody who knows a lot about that.

as far as lubricating is concerned, 10W40 is the same thing, no matter who is producing it. so it's a mystery to me how come that fuchs showed so much better then castrol. it should be the same. maybe becouse it took time to clear-out 5W30?
ask anybody, and they will all say that 5W30 SHOULD be better for gearbox then 10W40 simply becouse it's thinner in all conditions. why it is not so???? I dont know.


also, the reason why you had a residue for such a long time might be becouse previous owner treated gear oil with some additives? just a thought.

now, I would really hate to change from 5W30 to 10W40 and find out that gears are harder to change, or it takes 15 minuites in the morning to warm it up for normal driving.
so, please, keep me posted about this MT-90, my decision will depend on your experiences.

 

Ok, so forget the Redline MT-90, irrespective of their claims this was NOT good at all. It caused severe baulking up when cold. The box wouldn't change from first into second at all when cold. Took about a 5 mile drive before it warmed up and started to change nicely.

Once warm it was EXTREMELY smooth it must be said, like a hot knife through butter. BUT and this is a big BUT when in reverse I got a severe judder/shudder. Interestingly enough this same shudder was present when I got the car and at that time it had Comma SX75W-90 in it. So clearly something in gear box oil causes a reversing judder/shudder.

Anyhow I have put the 10W-40 back in and she is good as gold again, so will stick with that.

Remember as I stated at the outset the oil must be changed every 20K miles. I cannot understand why Chrysler agents have not been doing this when it clearly states in the CHRYSLER SERVICE MANUAL that it must be.

Perhaps it is because in the owners manual all it says is "CHECK MTX OIL". Obviously some muppet, who has no knowledge of oil and the impact of SHEAR stresses on motor oil, wrote the owners handbook.

Anyhow I hope the time, effort and expense I have gone through in this letting experiment will help others.

 

Ok I`m getting worried, I`ve only just got this car and I`ve read all about gearbox failures, I`ve never changed gearbox oil before but I have changed plenty of engine oil, My question before I get under the car at the weekend to have a look for the drain plug and fill plug, can anyone tell me where abouts on the box they are and what spanner/allen key I need. Also which oil to use?? and how many litres to buy, I`m towing a caravan at the weekend and I`m getting very concerned.

At the moment gear changes are very smooth.

Thanks

Pete

 

First confirm what car you have

is it

1) A 1996 - 2000 model

or

2) A 2001 and up model??

And what engine??

 

From his other post, peterwxm's is a 1999 2.5 TD, but mines a 2001 2.5 CRD so advice on both would be appreciated as I need to do this also.

 

I have already answered these questions for both models earlier in the thread and in fact you even thanked me for the advice on your CRD and said you were going to phone Chrysler just to make 100% sure on the ATF+4 spec ????

 

Hi Its a 1999 model 2.5TD, So from reading through again, can I conclude that we can either use a good quaility fully synthetic 10w-40 oil or a gear box oil which is GL4 or less (which is better?) and change this every 20,000 miles?

Also before getting under the car, can you please give advice on what spanner or allen key to use and where abouts on the box are the drain plug and top up plug, pics would be nice if anyone has any

Thanks for any advice

Pete

 

Don't know the allen key size off the top of my head. I have a set of sump allen keys and have never really check the size just pick them up till I find the one that fits.

I suggest you stick with a 10W-40 if you look at page 126 of your owners manual it will confirm this for you. I don't think it really matters fully synth or semi synth to be honest as long as you change it every 20K miles.

TIP: - Remove the rubber filler plug whilst draining it will make it go much faster. The torque setting for the drain plug is 23NM.


My gearbox, although it was changed less than 25K miles ago has dodgey synchro's and this was caused 100% by uneducated muppets, claiming to be "gearbox specialists" putting in a unsuitable gearbox oil. Additionally whilst they charged the previous owner just under £2000 for the job claiming it was a "brand new gearbox" they were of course talking out their rectal orifices. I doubt strongly that Chrysler would use silicon sealant around joints to the degree that it squishes everywhere. But of course as 99% of all car owners know the square root of sweet fanny adams about cars they blissfully believed them.

Due to this I am experimenting with a variety of oil options to try and smooth out the notchiness from my change. I have just purchased 3 quarts of Amsoil MTF so will soon be reporting back on it's suitability. However if you read my previous posts. Out of 5W-30, Redline MT-90 and 10W-40, thus far the 10W-40 has shown superior characteristics.