Hey people so much confusion on gearbox oil
what should i use for my roadster manual gearbox

 

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14 mm 17 mm
I bought the Pennzoil synchromesh on some reviews posted online but haven't changed it yet. I changed my manual transmission fluid a couple of years ago not much difference. If you diy you'll need a 14 & 17 mm hex socket/wrench for the tranny and differential . Do not drain your fluid until you break loose the fill plug !

 

hi thanks thats it see read so much even in manual put in 5/20 engine oil i thought it strange mind
so the trans fluid it shall be im in uk so dont know what ill get have to search around

 

Engine oil is NOT the issue. Do NOT use gear oil. Many, many OEs will use transmission fluid in their manuals, as the oil is already in use on the assembly line for automatics, and the thinner viscosity results in better EPA ratings. It doesn't mean that it is the best thing to use in the trans. Several other Chrysler manual gearboxes came with ATF in them, and owners found out very quickly that flushing out the ATF, and replacing with *good* synthetic engine oil resulted in better shifting and better life, especially when being pushed. This subject has been discussed many times, but FWIW, I use Mobil 1 High Mileage (the HM part is very important!) 5W-30. We have thousands of trouble-free miles on ours. One of our cars is sitting at 218K miles, and shifts like new. IIRC, spec is 5W20, which may be fine in colder climates. We live in the south, and that extra bit of viscosity is just fine. Before anyone squawks, I use the identical fluid in my SRT-4 transaxles, which use the same synchronizer materials (plus a Quaife ATB differential). Those came with ATF+4 from the factory. Chrysler engineers quickly let it be known to enthusiasts to switch to the Mobil 1 HM 5W30, and that entire community has never looked back. If a high end fluid is of interest, I have used Torco MTF in those same transaxles with great results, but have not tried it in the Crossfire, as it just isn't being pushed hard enough to justify it, IMHO. The big thing is under no circumstance should you use gear oil (ie 75W90, 80W90, 75W140, etc) in these transmissions.

 

I've had two manual roadsters, I put Mobile 1 5W20 in both on advice from guys here who know more than I do. It improved shifting into 2nd in both cars.
There is a Mercedes-specified manual oil, but I've not gone to the trouble of changing to it, since I'm still under 25,000 miles on the oil we put in there in 2017.

 

great news i shall try find that oil ,sorry are you in the uk i am and have not heard of mobile one hm but i shall try find it thanks so much

 

seems the best advice ive come across really alot of people say to use 5/20 so im going for it thanks

 

latest fluid from mercedes
https://www.needswings.com/manual-transmission-fluid

 

From 2005 through 2018 I had two XFires with manual trannys, a 2005 replaced by a 2007. During that time period I tried numerous fluids to improve shifting including M1 motor oil, ATF, Amsoil trans fluid, etc. All worked initially, but soon the 1st to 2nd gear crunch returned along with tough cold shifts. Finally I tried the MB factory fluid from NeedWings and the shifting issues were resolved permanently. Since this is the identical fluid that MB put in the comparable SLK320, it stands to reason it would work in the XFire tranny. There are a ton of posts on this topic, and below is one of many.

https://www.crossfireforum.org/forum...-question.html

 

Enough said
This is reason #275 (more or less) as to why it’s best to defer to and trust the professionals

Needswings always comes through. Get the approved fluid as identified by Rob and stop worrying if its correct

 

thank you both, also, IN STOCK AND READY TO SHIP.

 

just confused everyone says different so is that gear oil or engine oil i dont have any gear change issues but when driving slow in first and second leave off throttle i can hear a faint noise

 

Again, do NOT EVER use gear oil. NEVER! The safest recommendation is to use the official oil from MB, available from Needswings.

 

isnt that gear oil then looked for it says gear oil on bottle
but i have this number mb 235.10. Is this correct please but then i go on comma oil and it says use 5-20 engine oil lol im so confused

 

The Germans often refer to things a bit differently. When it comes to the OE stuff, I'm sure it is OK. When I say gear oil, I am referring to the more industry accepted definition of a heavy oil, and it is commonly found in weights, such as 75W80, 80W90, 75W145, etc. Those are heavy, thick oils, with a high surface tension. As such, they will not flow into the nooks and crannies of the shifting gearbox quickly enough, and will then fail to lubricate properly. Now, you will use those types of lube in the rear differential, but that is a completely different setup, with regards to the bearings and mechanisms inside.

The MB fluid is recommended for the SLK, and hence the Crossfire. I will still stand by and tell you that Mobil 1 High Mileage 5W20 or 5W30 will work just fine. The High Mileage (HM) is just a version of Mobil 1 (M1) that has a chemical makeup that lubricates better. It actually is the "old" M1 formula that still had ZDDP and sulphur in it, which has been removed from modern formulas of Mobil 1 for EPA requirements in engines. The High Mileage version lubricates better than the standard M1 you see on the shelf. You can use it in any engine (of the correct viscosity) without any ill effects, other than an oil that works better at being oil. Others have used more specialty fluids, like Synchromesh with good results. I found Torco to work better than Synchromesh in other Chrysler gearboxes, but it is also much more expensive. Motul also makes an MTF equivalent. All of these lighter oils will probably be just fine. If you have grinding issues, you may be using too 'thick' of an oil, or it is too cold where you are for that oil, or more simply, your synchronisers are wearing out and/or your clutch is not completely disengaging.

We went through a round here where heavy gear oil was being recommended, and it resulted in thrashed transmissions. That's what we want to avoid. So again, no 75Wxx, 80Wxx, 90Wxx ,etc.

Since people have had good luck with the MB approved fluid, that is probably your easiest/safest bet, if you still have questions about it. We have a great vendor (Needswings) who stocks it. Hard to beat that.

 

ok thanks for clearing that up im in the uk so cant find mobile one hm so if i go for the mb 235.10. I should be ok then yes
my gears are smooth but just have a small noise when driving slow in first and second when i leave off the gass pedal very quiet noise but really dont know when the oil waa changed if ever car is on 86000 miles now

 

I think you're probably OK. We changed gearbox oil in one car at over 200k, and we could tell it had never been changed. The oil actually appeared passable when we looked at it. Still going strong.

 

ok ill get some mb oil then would you say these gearboxes are a little whinny maybe or dead quiet when i shut off my motor with clutch out i get a small rattle sound but with clutch in no noise im probally being fussy now mind

 

Actually, 75W90 gear oil has about the same viscosity as 5W20 or 5W30 engine oil….

https://cimg0.ibsrv.net/gimg/www.cro...5a93bf5437.jpg