ZF 5 speed transmission wanted

[SpeedModel]

I'm interested in buying a ZF 5 speed for my 250SL. Please message me if you have one for sale.
Thanks!

[mdsalemi]

These are exceedingly rare, and quite costly if you’re lucky enough to find one. Parts hard to find so repairs not easy either.

That being said there are alternatives.

It’s a topic at PagodaFest next week.

[SpeedModel]

Hello Michael,

I would like to join everyone at the upcoming Pagodafest, but I am already committed to be at the Georgia Tech vs. Wake Forest game next Saturday (Go Jackets!). I have briefly looked at a couple of the other 5 speed gearbox conversions that I found online, but the gear ratios offered do not seem ideal.  With that said, I would very much appreciate hearing any solutions that are discussed at Pagodafest.

Eric

[mdsalemi]

I expect that some of the topics will be eventually ported to the Tech Manual...
But you have to be a full member for access!

[DavidAPease]

But you have to be a full member for access!

...or to attend PagodaFest.

 
     -David

[SpeedModel]

I haven't been on the forum in a few months and my subscription expired. Just renewed it. Enjoy Pagodafest.

[Raymond]

"have briefly looked at a couple of the other 5 speed gearbox conversions that I found online, but the gear ratios offered do not seem ideal."

There are at least two 5-speed options with gear ratios that are ideal.  I'll explain them at PagodaFest on Saturday.

[SpeedModel]

Unfortunately I will not be able to attend Pagodafest this year, but I am hopeful you will post details about 5 speed conversions on the SL113 site afterwards. I have looked at a complete TREMEC T5 5 speed conversion kit for a W113 offered by a company in Tennessee, but the ratios they quote are 1st / 2.95, 2nd / 1.94, 3rd / 1.34, 4th / 1:1, 5th / 0.73.  First gear at 2.95 seems quite tall. 5th gear might be too, perhaps better at .80 or so. The Tremac T5 in a 1986 Mustang SVO looks like it might be a better option if available new. 1st gear: 3.50:1 (some are 3.35:1), 2nd gear: 2.14:1, 3rd gear: 1.39:1, 4th gear: 1.00:1, and 5th gear: 0.78:1

[rwmastel]

When you say a ratio looks too high or low, what are you comparing it to?  Don't forget about axle (differential) gear ratios.

[Benz Dr.]

If you are able to find a real ZF transmission you will need more than the gear box. The bell housing is also ZF as is the rear transmission mount. Front section of the driveshaft is shorter as is the shift tube and stabilizer rods. Other than those things everything else is the same.

I have seen just the gear box for sale which could be good for parts but is otherwise just a door stopper.

[SpeedModel]

I'm comparing the TREMEC T5 ratios to the ZF S5-20 as optionally fitted to the W113. The differential in my 250SL is a 4.08.

W113 ZF Ratios
1 3.92:1
2 2.215:1
3 1.418:1
4 1:1
5 0.848:1
R 3.49:1

[Art]

I just completed a 5 speed conversion with a T5
It’s not the simple bolt in like everyone thinks and hopes.
And it works amazingly

[Alex D]

Totally agree with Art. Tremec  T-5 is nice, but was a real pain to install - no where near as easy as they claim.  I would only suggest if you are highly mechanically inclind, and are ready for a lot of frustration.  Wrong parts, missing parts in the kit, poor instructions.  If you can get thru the frustration and aggravation it's worth it, but be ready. Not for the faint of heart.

I have warned several people who pm me about it, some listened some did not. 

[mdsalemi]

I know the pain that Alex went through in getting the 5 speed installed properly.

Keep in mind that there were two broad types of the Borg-Warner/Tremec T5: world class after the mid 1980s, and non-world class prior. The latter models considered more robust.

People are sourcing these from all kinds of places, and understand that there were something over 200 different versions made. Many of those with different gears have different 1st gear and 5th gear; varied to the torque of the engine it was mated to.

Most people get these not for the 1-4 but for the overdrive 5th gear, I'd imagine, in the Pagoda application.

[SpeedModel]

Here is a link to a long list of T5 models with their tag numbers, applications and ratios. https://www.britishv8.org/Articles/Borg-Warner-T5-ID-Tags.htm. Note the link is from 2007, so newer T5 versions are not included.

[Alex D]

The Tremec T-5 transmission was not the problem, transmission it's self is perfect.  Drivenman in TN buys the Tremec T-5 transmission then Drivenman puts together the conversion kit  including the transmission - that is where the problems are in the Drivenman conversation kit. 

Anyone can buy the transmission by it's self about $2k.  It's the clever marketing from Drivenman that makes you believe it's a simple "plug and play" conversation - it is NOT, far from it.

[Benz Dr.]

I have a saying in my shop ( actually, one of many )

" Nothing is simple."

Looks like this conversion fits nicely into that notion.

[Art]

Another thing everyone overlooks is the gear ratios really do not matter.
I hope everyone is driving there car sensibly and it is not a race car
First gear in Both the auto and the 4 and the ZF 5 speed are almost useless and way to low. The 4 gear in all are 1-1 ratio.
The thing everyone wants is the overdrive in 5th. That way you can actually Cruz at 60 mph without the engine screaming. 
Crazy enough I used to have a 280SE and towed a 18 foot ski boat.
That car got the best mileage towing at 80 mph screaming.
I do have a 280sl that was an auto and now has a ZF5 so I have had and driven all of the variations.

[Raymond]

Tremec is no longer making all of the variations they did in 2007.  The demad for manual transmissions is RAPIDLY declining.  As near as I can tell, I was the first to install a T-5 sixteen years ago.  I had less trouble working with a local transmission shop than the folks with the "Dirven Man" American Powertrain kit.  Our engines have plenty of torque to handle the tall first gear and the T-5 actually makes 1st a practical, useable gear. 

[Benz Dr.]

Depends on the rear axle ratio. All cars sold with ZF 5 speeds used 4.08 as the standard rear axle. This was used in my own car so I changed it to a 3.92. Just that bit higher ratio made my car nicer to drive and first gear is now less agricultural.