I thought my mechanic knew what he was doing until

[e55amgbenz007]

I took my 03 G55 to have my trusty mechanic flush the fluids. I have known him for approximately 5 years. He is from Finland and has been working on, racing and building cars for the past 30 plus years. There a re always Ferarris and rare cars in his bay being built or worked on. So naturally, I do not second guess or question him in regards to his abilities and/or capacity to work on automobiles. Long story short.... Both of us being Redline fans, I gave him a case of MT-90 for the transfer case and a case of 75w90 to flush out the differentials. I got the car back with the case of MT-90 gone. He had put the GL-4 MT-90 in the diffs and tried to justify it with some contradicting [censored]. I told him to come pick the car up at my house and use the proper GL5 75w90 for the diffs. He took the car this morning to rectify the wrong. However, he adamately states that a GL-4 lube is okay for my AMG differentials. Have I been smoking too much? Or should I look for a new mechanic? Any help is appreciated guys.

I apologize for posting this in the regular oil forum but I was hoping to get as much attention as possible. This is really disconcerting to me.

 

[e55amgbenz007]

I took my 03 G55 to have my trusty mechanic flush the fluids. I have known him for approximately 5 years. He is from Finland and has been working on, racing and building cars for the past 30 plus years. There a re always Ferarris and rare cars in his bay being built or worked on. So naturally, I do not second guess or question him in regards to his abilities and/or capacity to work on automobiles. Long story short.... Both of us being Redline fans, I gave him a case of MT-90 for the transfer case and a case of 75w90 to flush out the differentials. I got the car back with the case of MT-90 gone. He had put the GL-4 MT-90 in the diffs and tried to justify it with some contradicting [censored]. I told him to come pick the car up at my house and use the proper GL5 75w90 for the diffs. He took the car this morning to rectify the wrong. However, he adamately states that a GL-4 lube is okay for my AMG differentials. Have I been smoking too much? Or should I look for a new mechanic? Any help is appreciated guys.

 

[Herz]

sometimes mechanics make mistakes I would expect him to right his wrong. But if he tried to justify it I would doubt him in the future. Or possibly he does have reasoning for doing what he did I dont know?

Basic line is some people make mistakes if hes been your mechanic for a while and you have trusted him forgive him and move on.

If you dont feel comfortable with him, find a new one.

 

[Johnny]

If your owners manual calls for GL5 then that is what he should have put in there. Just because he works on Ferraris does not make him an expert. Just for fun contact Red Line and ask them.

 

[Quattro Pete]

Does your differential contain hypoid gears? That's the only case I can think of where the MT-90 should not be used.

Still, if you asked him specifically to use 75w90 GL-5, then that's what he should have used. That's what I'm running in my rear diff as well.

 

[Johnny]

See my reply in your transmission section post.

 

[e55amgbenz007]

It actually states that the MT-90 gear oil is not suitable for hypoid gear diffs on the Redline site! All data diy (the same site he uses) calls for a hypoid gear oil. I would assume that this indeed, is a hypoid gear differential. That would mean that the Redline cannot be used in my diffs. He should have absolutely known that. But aside from the mistake, he continues to justify his decision which makes me think that is indeed not as smart as I give him credit for.

 

[d00df00d]

I can't recall ever seeing a diff that didn't spec GL5, even for what I would think is a light duty application.

This link seems to have a few opinions about viscosity but it's all GL5: http://www.benzworld.org/forums/g-class/1379152-photo-diy-differential-oil-change.html

 

[e55amgbenz007]

Yes Pete, since a hypoid gear oil is stated as needed for this tranny, I would assume that it is indeed a hypoid diff. However, on Redline's own site, it states that the MT-90 should NOT be used with hypoid diffs which is why I am wondering why he continues to justify his stance.

 

[Herz]

then he needs to be fired!

 

[d00df00d]

Did you point that out to him?

 

[unDummy]

Get a new mechanic.

If someone screws up, they should admit it. When they don't, they're just hacks. Having fancy cars to work on doesn't mean they know what they are doing.

The local shop here services nothing but daily drivers and proverbial 'junk' cars that we poor folks drive, and wouldn't make a mistake like that with a Yugo.

Also, its for you to make sure what you buy is acceptable for your application per the owners or service manual.

 

[CATERHAM]

Notwithstanding he didn't follow you instructions, a quick email to Dave at Red Line asking if the MT 90 should be changed out and the 75W-90 diff oil installed should put the question to bed.

If he still doesn't come clean find a new mechanic.

 

[Quattro Pete]

Originally Posted By: e55amgbenz007
Yes Pete, since a hypoid gear oil is stated as needed for this tranny, I would assume that it is indeed a hypoid diff. However, on Redline's own site, it states that the MT-90 should NOT be used with hypoid diffs which is why I am wondering why he continues to justify his stance.

Seems like you've got your answer. The mechanic should have known that. So, he either didn't know it and is playing dumb, or he knew it, but made a mistake, and now does not want to admit it. In either case, he still needs to put the right fluid in there.

 

[ARCOgraphite]

Originally Posted By: unDummy
Get a new mechanic.

If someone screws up, they should admit it. When they don't, they're just hacks. Having fancy cars to work on doesn't mean they know what they are doing.

The local shop here services nothing but daily drivers and proverbial 'junk' cars that we poor folks drive, and wouldn't make a mistake like that with a Yugo.

Also, its for you to make sure what you buy is acceptable for your application per the owners or service manual.


The yugo spec 15-20w40 HD motor oil for the transaxle. Never had a prob with it. Even with a 1.3L SCCA motor in there.
Yes a former FIAT 128SL 3P and then ZASTAVA owner - hey I had to do something with all those race parts lying around the house

 

[mechtech2]

The good news is that no damage occurred.
YOu have a nice flush now.
Like most mechanics, he is not conversant with lubes and oils.
And most of all, if he did not agree to what you specifically told him to do, he should do some homework first, and at least tell you beforehand!
He should pay for the loss of the fluid he put in, BTW.
Fire him? I dunno... He may otherwise be careful and conscientious .

 

[01rangerxl]

If you specifically told him to put the GL5 in the diffs, he should have done that. It's not his decision because it's your money.

And I have never heard of a diff using GL4. Show him the Redline site and the Alldata stuff. At least do it for the guy's other customers before someone else gets GL4 in their car's diff.

 

[mcrn]

So he came and picked up your car? So you are not there to watch the work. How do you know he will change it out? If he really thinks he is right and you are wrong he might not feel the need to actually do the work. But if you trust him enough to take his word for it and he has been good to you so far then I would stay with him.

 

[e55amgbenz007]

I have known the guy (in an automotive kind of mechanic buddy guy way) for about 5 years. I trust(ed) everything he said with regards to autos. He is a very seasoned and knowledgeable guy. He put the 75w90 in the diffs. I know for sure as for when he returned I questioned him as to whose fluid he used. As I suspected, he used mine....again. I called him on it right then and there. I am now out an extra 40$ in fluids due to his incompetence. He stated that he would give me the fluid back as he had it in the shop. Then WHY would he have used mine if he already HAD the fluids and it was HIS mistake? He was hoping that I wouldn't notice. I told him that he was full of it (in a not so nice manner) and told him to leave. I thought he was a decent guy.....but I suspected a cheat for a long, long time. That suspicion was finally confirmed

 

[JohnBrowning]

Because he can not admit he was wrong and his customer caught his mistake! I was trained to be a mechanic and did for a year before deciding it was not for me and I went back to college. So the other day my Dad went to AutoZone while he was out getting Grocery when the CEL came on. So it tells him Bank 1 postion 2 O2 needs to be changed. So he changed it and erased the codes and still came back on. So I said to him this is simple get your VOM and a propane torch and I will show you how to tell which one is bad. I explained that at around 600°F it had to have X voltage to be good and if you remove the heat the voltage should drop in X amount of time! He did not believe me when I told him that the the O2 sensor produced a voltage on it's own.......I told him Ohms of resistance is unreliable and no real mechanic would use Ohms...Well the Toyota service manual said to use Ohms of resistance but they all passed that test. So I figured you know what the Internet is full of information so I went to Youtube and typed in O2 Senosr Testing and Alpar Mopar Site had a video of exactly what I explained to him. Even then he did not believe me so the next day still unable to figure it out he tried my method and in about 5 minutes he located the right O2 sensor that needed replacing. He still could not admit I was right! This has happened about 20 times in my lifetime where I have been right on something like this and he was wrong and he simply can not admit he little snotty nosed brat of a son could be right especially when my advice contradicts something in a book. He takes field manuals and service manuals as if they are gospel!I on the other hand seldom have a manual but because I understand how things work I figure things out rather quickly even when I do not have a book.Pride is a really tough thing to swallow and so is crow! I was trying to be helpful though not trying to prove him wrong.

I on the other hand am just the opposite I am usually the first around friends and family to admit I am wrong or was wrong on something.

I have a friend that is a Doctor out West and his Mom and Dad will not listen to him to save their lives!He is the type that is about 20 years ahead of most Doctors so itis only when years latter their Doctor tells them the same thing their son told them that they do it! I do not under stand it but for some reason Dad's,Friends,Family and most of all Proffessional in Skill Trades cannot admit it when a younger family member or a client is right and catch's them making a serious mistake or knowing more about a given product then they do!!!I just know it happens!

If he has other wise been good to you and and always done good work and charged a fair price for the market you are in i would not write him off! Surely your brother or sister or spouse has done something similar and not been able to admit you where right or stuck by a losing position just out of pride!So I would let this one go since you caught it early and no harm was done. I might only next time give him enough of any one product to do the job and even label the box's diff/transmisission etc.....

Mechanics are usually Alpha Males and they have the Alpha male baggage even if they are from Finland they have Alpha males their too!While I grew up in an environment that rewarded alpha male behavior and I can pass for one if need be it is not my real nature! That is one reason why I did not want to be a mechanic while I understand them well I did not want to be around that lot any more then I had too!Alpha males are hard to work around if you are not one as well!