Mack 9 Speeds

[Lmackattack]

I have driven them both over the road and in the dirt and I like them alot because it gives you more gears to work with and it has an overdrive to keep RPMs low on the big roads. However I have heard quite a few people say the 9 Spd is not a good dirt truck transmission because there is a problem with the range selectors in the gearbox?? any truth to this

has anyone had a major issue with them?

[bubbamobilin]

I have a t2090 in an '89 Superliner. The range synchro and clutch pack has been out 3 times. Mack upgraded these parts and the last 1 has lasted almost 4 years and still going strong. Since the last 1 was installed I changed the way I shifted. A Fuller 9 shifts L,1,2,3,4,5 on the low side and 6,7,8,9 on the high side. Shift a Mack 9 L,1,2,3,4 on the low side and 5,6,7,8,9 on the high side. This way the trans is turning slower when you shift from low to high range thus saving the clutch pack and synchro.

[Lmackattack]

thanks for the reply

I am asking because I have mixed reviews

I am driving my friends dump truck on some weekends for the last year and it has the 9 speed. I noticed the range change was not smooth at all. He replaced the clutch pack and a year later its doing it again.

Another friend has the same trans and we went from Chicago to N.Y and back with not one scratch from shifting it.

the local truck puller has a superliner with a jused up V8 with the 9spd and he's heard its a tempermental trans but has not given him problems...yet

[FIREMAN]

We had a Fuller 9 speed and a Mack 9 speed in a couple of CH's and never had any problems at all. In fact the Fuller was under warrenty for 750,000 miles if you used synthetic gear oil.

As a matter of fact, if anybody knows where I can find a Mack or Fuller 9 speed for my 82 R-Model let me know. I want to have more road speed. Right now, I have a lo-hole 6 speed with 4.17's it only runs 62 MPH @ 2100 RPM's

Thanks

Larry

[b61mack]

If you use a direct transmission it dosnt make it run any faster if you have install a 9 or 10,13 speed, if you want to go faster you need an overdrive transmission, i have a double overdrive 13 speed roadranger. i also have a bellhousing , mack to fuller trans. Ron

[Superdog]

The T2090 is an overdive trns.,that's why he's looking for one.As far as it being a reliable transmission,the one in my Superliner has close to 1.5 million on it and the only tranny related problem I've ever had with it was the splitter valve started leaking and I had to replace it and an air line broke.

[Lmackattack]

I spoke with my mack parts guy today and he said there were a few revisions with the 9 speed. the range selector/clutch plates , some gears, and counter shaft were the some of the changes. he said that in most cases it was because the drivers did not know how to shift them properly, He also said that some of the early productions had problems people speak of, mainly with the clutch plates, he said that they were very stiff and caused early wear on some of the internals. the plate revision had a softer engaugement that reduced wear.

I guess if the trans was shifted correctly or had the revisions made all will be ok

I like the 2 stick for the city but the direct drive is no fun on the highway

thanks for all the input

Trent

[David]

Larry,

I have a RTOX14610 with Mack bellhousing for sale. Call me at 919-932-3344.

David

[FIREMAN]

If you use a direct transmission it dosnt make it run any faster if you have install a 9 or 10,13 speed, if you want to go faster you need an overdrive transmission, i have a double overdrive 13 speed roadranger. i also have a bellhousing , mack to fuller trans.        Ron

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Hey B61mack:

How much? What kind of shape? And Where in the world is Delphi IN

Thanks

Larry

[b61mack]

Fireman it is a 9513, great shape, Delphi is 70 miles north of Indy, i will take $500 with the mack bellhousing. i had 4.33 rears in my B model, installed 3.87, i thought a double overdrive would be much so i installed a single overdrive 13, took the top cover off checked it out, shifted good, with the single overdrive with 22.5 hi tred tires it runs 82mph , i think you have to use a pull type clutch but do not know fo sure Ron

[FIREMAN]

Fireman  it is a 9513, great shape, Delphi is 70 miles north of Indy, i will take $500 with the mack bellhousing. i had 4.33 rears in my B model, installed 3.87, i thought a double overdrive would be much so i  installed a single overdrive 13, took the top cover off checked it out, shifted good, with the single overdrive with 22.5 hi tred tires it runs 82mph , i think you have to use a pull type clutch but do not know fo sure          Ron

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Thanks Ron

I was really looking for a 12513. the price sounds great though. If I go that way I'll get back in touch with you.

thanks

Larry

[kharless]

I replaced the 6 speed in my 1988 R686ST with a Eaton 9 speed direct. I really did'nt gain any highway speed. I should have used the overdrive(14609b instejava script:emoticon('', 'smid_10')ad of 14609a).

[FIREMAN]

I replaced the 6 speed in my 1988 R686ST with a Eaton 9 speed direct. I really did'nt gain any highway speed. I should have used the overdrive(14609b instejava script:emoticon('', 'smid_10')ad of 14609a).

Thanks Kharless

Alot of things have changed since that post for a 9 speed. I have since purchased a 2000 CH to use everyday and decided to park the R-Model till it qualifys for antique status. I'm just going to keep the R as it is.

Thanks for the info

Fireman

[mudslut28]

I know its outdated but I had one 9 speed and it had clutch pack trouble as well. I loved the tranny and the way it shifted but I didnt have any luck on reliability. This was hauling coal in an RD800 though.