ZF-5spd Single or Dual Mass

[LCAM-01XA]

ZF REQUIRES synthetic.

I'd like to see some proof of that?

Franklin, the Pennzoil stuff is not synthetic either. Don't know what's special about it that makes it so expensive, must be the additives inside it as from what I gather every other synchromesh oil that does the same job carries a similar price tag. All I know is it keeps the transmission quiet, it's easy to shift when it gets cold out there, and overall it keeps the trans cool even under heavy load.

The Dex-Merc, that one I'm quite skeptical about, in my experience with running that junk in power steering systems that officially call for it, after switching to something else (be it dedicated PS fluid or heavy equipment hydraulic fluid) there has been a noticeable drop in temperature of everything said fluid runs through. Apples to oranges I know, but still, temperature is a direct by-product of friction, so to me this suggests that things are now moving easier. In a transmission with many things rotating at high speed, low friction is good. Thus I choose to run oil that is made specifically for such an application, as opposed to the more of one-size-fits-all ATF the factory calls for. The transmission in question is reasonably-high mileage unit that has never been rebuilt yet it looks like brand new on the inside, however according to its previous owner it only ran ATF till the first time the manual called for fluid change and ever since then it's been swimming in synchromesh oil. And what came out of it when we opened it for inspection before installing it in our truck sure didn't look like ATF, or gear oil for that matter...

 

[cpdenton]

http://www.zf.com/media/media/docum...ments/usa_4/S5-42_47__47M_Service_manual_.pdf


Page 65 of this document denotes th type of fluid and amount needed. It states that gas engines can use Mercon V, but has a separate notation for zf5's that are behind a diesel that says it requires Mercon V synthetic.

Btw, royal purple synthetic in mine. Works pretty good to control rollover noise as long as I am not in gear under 1000 rpm, which is in the service manual too. Says to fix the grinding noise heard in gear under 1000 rpm by not running it under 1000 rpm! Haha

 

[LCAM-01XA]

Well that's rather interesting! About the fluid specs I mean, the fix for in-gear noise under 1000 RPMs is just plain funny!

Since I ended up on page 64 of the manual at first where it lists the gear ratios there, I'd like to ask the following (somewhat off-topic) question: does anyone know what diesels got the 5.72 first gear? So far we have two S42s (German-made '89 and US-made '94) with 4.14 first, and I know of at least one '96 S47 (also US-made) with 5.08 first. Do I have to venture out in Superduty territory for a 5.72-geared diesel ZF?

 

[franklin2]

I am thinking synthetic wasn't even available back when these trannies were first put behind the diesels. I have no proof, but 1989 was a long time ago. I thought when they did come available, zf upgraded their specs and recommended the synthetic be used. If anyone has their old original owners manual, I would be curious to see what oil it recommends for a zf equipped truck.

 

[ironworker40]

That is a 1995 Ford manual that cpdenton posted. Look at bottom of page. My 1993 ford manual states mercon only

 

[reklund]

The clutch disc I just revmoved has 10 springs and the transmission had terrible roll over noise. Night and day difference between the solid mass with 10 spring clutch disc and factory dual mass flywheel set-up. Maybe, now with the rebuilt trans the roll-over noise would be less however I'm going to check into the cost of reinstalling the dual mass flywheel.

I fully understand your desire for the dual mass. If I could go back in time, Id do another dual mass too and have avoided a new transmission and multiple r&r jobs to chase noises and stuff.

That said, my single mass is quiet for now. Is it possible your disc was worn and loose in the hub? There are thousands of these single mass setups out there running quietly, so something must be amiss.

Keep us posted on what you end up with.

The synthetic -vs- conventional oil (in my opinion) won't have any effect on noise level. In chasing my noise I tried conventional and synthetic ATF, manual transmission fluid from Lucas, straight 30wt, and 20/50 motor oil with no change in noise level even if I overfilled the trans by a quart. The only thing that kept noise to the correct level in my truck was the correct disc and a new transmission. I now run conventional ATF, filled to the proper level from the fill plug, with no issues.

 

[franklin2]

That said, my single mass is quiet for now. Is it possible your disc was worn and loose in the hub? There are thousands of these single mass setups out there running quietly, so something must be amiss.

I think some of the variation from truck to truck depends on the state of tune of the engine and how smooth it runs. The zf seems to be a large amplifier of what's going on in the engine. A rougher running engine is going to make the tranny louder.

 

[catbird7]

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I bought the single mass set-up new and when I removed it there was less than 20,000 miles on it. See attached picture of disc. Under normal circumstances I would not be afraid to reinstall this.

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[catbird7]

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Regarding oil, I'll stick with manufacture suggestion from tag on side of trans. The re-builder suggested filling with synthetic trans oil, he was not brand specific.

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[catbird7]

I have found two different dual mass flywheels for sale. One is for normally aspirated 7.3 and the other is for 7.3 idi with factory turbo. I'm wanting to install this on an 1987 6.9 idi with ATS 093 turbo (not originally a factory turbo engine). Can I use either of these dual mass flywheels?

 

[Greg5OH]

from wiki recarding mercon V

The development of modulating and continuous slipping clutch converters has prompted the need to develop the MERCON V specification. Included are requirements to verify the anti-wear capabilities and anti-shudder characteristics of the fluid.

 

[laserjock]

You have to watch factory turbo parts. I think they are balanced different. If you have the rotating assembly all balanced together I suppose it wouldn't matter.