Narrowing a mustang manual rack & pinion

Has anyone ever narrowed a manual rack & pinion unit. It seems do-able, however I'm not a machinist. Theoreticaly, it looks simple. The unisteer unit that is sold to replace the Vega gear comes to mind. I'm building a three wheel vehicle that needs a narrow rack and I thought of possibly trying this. I know a lot of you have cut up some wierd shit and made it work, so... feasible? Any threads? Good / bad idea? Any info would be appreciated. Thanx, Norm

 

i looked into doing this before, and it seemes entirely possible if you have access to a lathe and possibly a tig welder (for the aluminum body)

basically, the rack would be offset, cause you can only really shorten the passenger side, luckily the tierod ends thread into the mainshaft, so you can just disassemble, cut it down, drill and rethread the shaft for the tierod.

he body of the rack can be narrowed a couple ways, i was thinking of trying to press it apart, and cut the steel tube down, and somehow press it all back together? or maybe just cut and weld the aluminum, depending upon how far you have to narrow it.

 

I remember seeing a article on narrowing a maual rack (maybe an Omni) back in (I think) the eighties. Might have been in Rodders Digest or one of the other lesser known/smaller magazines. Can be done, has been done, and narrowing it through the body (rather than the tierods) is the correct way to do it.

Far as I can recall, they narrowed and welded the housing then shortened (rather than cutting a chunk out of the middle) the inner main shaft of the rack and had a machine shop replicate whatever was on the end to accept the tierod.

 

On www.fatmanfab.com under the tech section there is a 2 part article on narrowing the manual rack and pinion. Lots of information there.

 

I went to Flaming River for a narrowed Mustang type R&P.
They don't give any guarentees with modified assemblies, but they did a great job on mine.
It did cut a little from the lock to lock..no big deal for me.

It's been a few years, so I don't recall the cost..

Give'm a call.

Mike

 

there are several ways to do this. You can cut the long end of the rack & have it rethreaded & machined to fit the stock tie rod then make a new bearing for the rack & boot for the tube. Or you can cut the rack & thread it 1/2 in fine & use a rod end & make a new tie rod & again make a bearing &boot end or splice the tube. You can also buy a centered rack & pinion that is center steer.

 

www.unisteer.com might be able to assist you.

 

It's do-able, as stated, but there are a lot of used circle track racks for sale out there. Typically they are just over 1/2 the length of the MII...

 

Thanx all for the info. The Fatman article was most informative. I think that I can make this happen. Thanx again, Norm

 

I narrowed this one twice. First it was in an Anglia. Now it is going into a smaller project car. No machine work was required.

 

We narrow R&P all the time downunder to suit IFS, front and rear steer. Always cut the rack shaft on the opposite end to the machined teeth as they are heat treated. All you need to do is re-machine the end so the rack end goes on as per OEM configuration and narrow the rack body to suit. When finished check your lock to lock as you may need to alter your steering bump stops.

 

I bought a Maval rack from Unisteer for my daughter's Nash Metropolitan project. They made it to my specs and it worked just fine. Was around $500 if I recall

 

I cut my Opel GT 6", six inches out of the housing and tig back, 6" off the long side of the rack and re tap the tie rod hole, piece of cake. Had to buy a metric tap $14.00

 

I need to ask why not shorten the tie rod ends ? I'm not using the m2 rack, I have the whole front suspension from 88 -95 Mustang and need to shorten it to 60 inch track. Thanks

 

You can't just shorten the tie rods and expect the geometry to be correct. The pivot points (usally under the boots) must be in alignment with the upper and lower a-arm pivot points or you'll have bumpsteer. If you narrowed the a-arms you would shorten the tie rods but if you narrowed the cradle (moved the a-arm assys in towards the center) you have to narrow the rack inside the pivots the same amount.

 

These links were posted by me in another thread a few weeks ago.

http://www.jalopyjournal.com/forum/showthread.php?t=658632 Thread link

http://www.webrodder.com/article.php?AID=393&SID=16&CID=11 Narrowing MII rack PT1

http://www.webrodder.com/article.php?AID=394&SID=16&CID=11 Narrowing MII rack PT2

 

As stated, you will have bumpsteer. The steering tie rods need to follow a similar arc to the lower A-arm. Not only the length, but as metalman points out the height they are mounted also affects bumpsteer.

 

Smaller?

 

These links don't seem to work.

Does anyone have links on disassembling one of these racks?

I need to chuck mine in the lathe to true up the aluminum body so I can make a clamp on mount and remove the original drivers side mount.

Thanks

 

That's what I did. Made by Sweet, $75 at the swap meet.