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Discussion Starter · #1 ·
My 6speed has a nice tight shift through the gears but I've decided to replace the gearbox oil with Royal Purple Syncromax to hopefully keep a nice tight shift, however at £16.00 per ltr + vat and postage does any of the Techs out there no how much oil the box holds ?
I'm not tight honest i'm not !!!!!!!
i just could not look at ltr bottles of R R oil i will never use just left sitting in my garage :crying:
 

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capacities are listed in your owner's manual.

you will need 2L - you won't use all of both.
 

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Changing to RP Synchromax on my beast at 45k miles did result in noticeably smoother shifting. We get quart bottles here in the states and I squeaked by with two. If you do a search here you'll find directions for doing this yourself, including some pointers on hand pumps that make the work much easier.
 

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I changed (my indy changed it) mine to RP and I think I'll be going back to BMW fluid. It is somewhat smoother shifts but not that noticeable to me. Something that was extremely noticeable was the notchiness on cold start ups. I've never had an issue like that prior to changing the fluid. The shifting smooths out within a few minutes of the car warming up but it is very difficult for me to shift into 2nd gear during the first couple minutes of driving now that it has gotten colder in the mornings.
 

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I changed (my indy changed it) mine to RP and I think I'll be going back to BMW fluid. It is somewhat smoother shifts but not that noticeable to me. Something that was extremely noticeable was the notchiness on cold start ups. I've never had an issue like that prior to changing the fluid. The shifting smooths out within a few minutes of the car warming up but it is very difficult for me to shift into 2nd gear during the first couple minutes of driving now that it has gotten colder in the mornings.
Odd, notchiness in cold starts is why I changed the fluid and had this problem go away with the RP. How many miles ago did you do the RP swap? Many folks on here have commented that replacing with any approved fluid will render some smoothness results, so it may just be a matter of time.
 

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Discussion Starter · #7 ·
capacities are listed in your owner's manual.

you will need 2L - you won't use all of both.
Cheers for the help chaps !!!!! :cheers:
2 ltr's that will save me a few £'s :applause:
As my owners book has capacities but not for gearbox or diff ?
'says filled for life' so keep your sticky fingers out
 

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<table bgcolor="white" border="1" cellpadding="5"><tbody><tr><td>Production</td><td>FROM : 1998/09/01</td> <td>TO : 2003/05/31</td></tr> <tr><td colspan="2">Engine</td><td>S62</td></tr> <tr><td colspan="2">Engine Oil</td><td align="right">6.50 Liter</td></tr> <tr><td colspan="2">Transmission</td><td>Manual</td></tr> <tr><td colspan="2">Transmission Model</td><td>S6S 420G</td></tr> <tr><td colspan="2">Transmission Oil</td><td align="right">1.75 Liter</td></tr> <tr><td colspan="2">Rear Axle Oil</td><td align="right">1.60 Liter</td></tr> <tr><td colspan="2">Coolant(w/o Air Conditioner)</td><td align="right">0.00 Liter</td></tr> <tr><td colspan="2">Coolant(with Air Conditioner)</td><td align="right">12.75 Liter</td></tr> <tr><td colspan="2">Brake fluid</td><td align="right">1.00 Liter</td></tr> <tr><td colspan="3">Remarks :
Final drive (rear axel), manual transmission: lifetime oil filing, during the Running-In Inspection gearbox oil change </td></tr></tbody></table>
 

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Odd, notchiness in cold starts is why I changed the fluid and had this problem go away with the RP. How many miles ago did you do the RP swap? Many folks on here have commented that replacing with any approved fluid will render some smoothness results, so it may just be a matter of time.
I guess its been about 300 miles ago? I'm beginning to wonder if I'm low on fluid or something?
 

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I changed to my gearbox redline MTL oils and shifting is smoother but at cold (-5celcius etc) first couple of minutes is stiff.
Please check compatibility of the fluid you selected with the transmission. A thread discussing fluid at length is on this board and I am fairly certain MTL eats at the synchros.

For the cost, BMW fluid doesn't differ greatly and it's the only fluid proven to work under all operating conditions made by a major lube manufacturer that can and does test to all ASME/SAE standards. I have serious concerns for small companies that don't do a full gamut of testing and doesn't publish technical data.
 
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Those are good, general references, but Redline or RP doesn't publish more info than general marketing buzz. I don't believe either are API certified.

This is the thread that I read through and drew my on conclusions on which lube to use: http://www.m5board.com/vbulletin/e3...279-getrag-6-spd-fluid-incompatibilities.html

Similarly, the rear diff also uses a unique fluid because of the viscosity with limited manufacturers that offer it.
 
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That's an awfully old thread (5-7 years) with a steep learning curve. However the OE fluid analysis is particularly insightful. I did not explore the internals of the 226 tranny 7 yrs ago. I've later learned it has no plastic parts to swell like the 233.

Today I'd be choosing the current LT2 fluid which superceded LT1, found in newer BMW trannys including the carryover 226. RP also appears OK for this application.
 

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I always thought we had the 420G in our cars.Same tranny in the M5 and 540i with maybe a few changes in the M5.
RP has proved itself over the years and the MTL Redline has been in quite a few cars I know for over 60K and the tranny still works.I remember a concoction from UUC ( the mixing of two different fluids ) to supposedly get rid of the Light weight fly wheel chatter,I think it was UUC.
I am putting synchromax in my car here soon to see what happens,a bunch of people like it.
The 420G is a pretty notchy tranny to begin with or at least everyone I have driven has been very distinctive in it's shifting of gears.
 

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I always thought we had the 420G in our cars.Same tranny in the M5 and 540i with maybe a few changes in the M5.
RP has proved itself over the years and the MTL Redline has been in quite a few cars I know for over 60K and the tranny still works.I remember a concoction from UUC ( the mixing of two different fluids ) to supposedly get rid of the Light weight fly wheel chatter,I think it was UUC.
I am putting synchromax in my car here soon to see what happens,a bunch of people like it.
The 420G is a pretty notchy tranny to begin with or at least everyone I have driven has been very distinctive in it's shifting of gears.
Getrag type D = Getrag type 226 = BMW S6S 420G

Assuming the fluid is proper type (and reasonable condition with less than 50K mi on it) and level not low, notchiness results from wear or bent/distorted parts. This damage can sometimes be masked or managed with certain fluids, but the transmission is already degraded to some degree. When notchiness and baulkiness become serious, the linkage and associated synchro assemblies can bind and fail from wear and/or high shifting force. The wisest thing to do with a notchy tranny is change the fluid often using proper lubricant and shift gently or skip gears when it's behaving badly. When the problem becomes chronic or you get tired of babying it, you should have it rebuilt to address the design issues instead of busting metallic parts which often find their way through the gearsets and destroy them. I occasionally rebuild, upgrade and modify these trannys for racers. It is possible to optimize shift quality and fully correct the design weaknesses that cause such issues. This allows the tranny to be shifted quickly and aggressively without fear and you can run factory fill that ensures long gearset lifecycle without such symptoms. Selecting aftermarket fluids that minimize shifter notchiness is not the most thoughtful approach for maximizing lifecycle of shafts, gearsets, bearings, synchros etc.
 

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the current bmw mtl is MTFLT3, im using this currently and it seems to be preforming well. the shifting is smoother than the LT2, especially when cold.
 
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