m46 fluid

Hey guys, having hard shifts into 1st and 2nd when the transmission is cold, better when hot. Linkages, bushings are all good, shifting action is good when the car isn't running. Been digging around online and it looks like the consensus is type F is the way to go, that's what I've been running and what my manual calls for, though it seems some ask for a 10w30 oil. Talked about the problem recently at an autox event and a honda guy recommended trying a synchromesh fluid. From what I've read it looks like the m46s need an atf or fluid with some atf properties due to the electric OD/clutch, I am no expert when it comes to transmissions. Wondering if anyone has had any improvement in worn synchro symptoms by switching to a new fluid. To clarify the fluid is clean and has been changed recently. The drain plug had some average metallic fuzz on it but no shiny chunks.

I've used synchromesh on worn out WC t5s with good results, but my m47 is happier with mobile-1 atf. I've also had good luck with synthetic 10w-40 in my old m46.

The synchromesh is definitely slower at changing gears, less of an immediate "snick" when shifting.

With a M46 you need Type F fluid. If you want better shifting I would go with Amsoil full synthetic trans. fluid. One thing you might try is move your reverse lockout bracket over just a little. I was having a hard time getting into 1st, I moved mine over and BOOM drops into 1st easilty.

90volvo said:

With a M46 you need Type F fluid. If you want better shifting I would go with Amsoil full synthetic trans. fluid. One thing you might try is move your reverse lockout bracket over just a little. I was having a hard time getting into 1st, I moved mine over and BOOM drops into 1st easilty.

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I've been thinking I'll try a synthetic. I don't think this is the issue as all the gears are free when the car isn't running.

Whatever You do, don't try the regular ATF, regardless of what the producer or the label says.

I knew this before but for some stupid reason I trusted the oil seller and finally damaged my M46 syncros cause I didn't rechange the oil. The gears started to engage poorly and syncros create noise when shifting oimmediately after the wrong oil was inserted. I thought to myself I'll change it in no-time
Now 3rd gear can't be engaged anymore when the car is moving.

I run synthetic 10w40 in my m46 and it shifts & od works just fine

adamdrives said:

I've been thinking I'll try a synthetic. I don't think this is the issue as all the gears are free when the car isn't running.

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Clutch disengaging all the way?

Redline MTL works great. Been using it in my cars since 1997. Overdrive is happy, yet the M46 gearbox itself is happy as well.

You may want to also check your clutch free play. That is, if the 740/760 Turbodiesel cars are like the non-turbo cars with a cable clutch. I find that the 1-3mm toward the back of the car tends to make the clutch easier to slip, so I usually set it to the pre-'83 non-turbo 240 specs of 3-4mm toward the front with a return spring between the fork and the tranny mount bracket (or the eye on the tranny crossmember, if a 164 engine mount is being used). If the TD cars use a hydraulic clutch, maybe bleed it...

-J

Actually my dad made a comment about the pedal grabbing very low when he drove the car, so I do think the cable needs adjustment. I'll see if I can get that taken care of this weekend.