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Old 10-26-2018, 04:09 PM   #1
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Default Steering gear replacements

I have been doing a ton or reading on rebuilt, recirculating ball, steering gears like is used in most of our vans (I think Promasters are rack and pinion), while trying to find the right upgrade setup for my 1996 Buick Roadmaster wagon, which has a horrible variable assist system stock, to firm up the steering and get some road feel. What I have found is kind of concerning in relation to the quality and application accuracy of nearly all the "normal" rebuilt units available.


Steering gears are often very, very, similar between various models and will use most of the same parts in them, with the differences being indiscernible form the outside. GM has used some of the housing gears since the 1960s, so many of the old ones would fit much newer vehicles, for instance. The problem comes in that the gear ratio and steering effort may or may not be the same between the different units. Sometimes the pump pressure in a different vehicles will also need to have the right gear to work the best. Having very similar, but different, parts is certainly not rare for lots of different parts, but it does appear that the gear rebuilders don't make sure the the right parts are in all there gears for the particular applications. When you buy a rebuilt gear for your van, you might get one that has a different ratio or effort, but will fit right in and function. The steering feel could be totally different, though, than the original was. I think a lot of people probably don't notice because the gear they replaced was probably in horrible condition and anything would be better, or maybe they get really lucky and get one that has driving feel they like better than the original was.



Along with the mismatched parts, the quality of the units seems to be very poor, with lots of bad ones from what appears to be almost all the rebuilders, including the costlier ones (like from NAPA). Leaks, binding, poor centering, noise, looseness (it was amazing how many complaints I found where they needed to be adjusted to the factory preload spec right out of the box), etc were very common. Sometimes people got two or three from their local parts store that were bad before getting one that was any good. Most of the issues are probably caused, at least according to people that had looked into it (mostly mechanics that had to keep replacing customer units for free) was that it appears most rebuilders just open up a used gear and look at the parts. If the shafts, worm, sector, bearings, etc don't show noticeable issues they aren't replaced. The parts aren't normally measured to see if the are within factory speced wear limits. They may or may not be polished for shafts. They are then reassembled with new seals and gaskets and called done. It is likely that none are ever put on a tester for centering or effort or worm to rack wear checked in the center compared to the rest of the travel. (They should be a bit tighter in the center to help feel without getting too loose other places)


I don't really know what the solution for the issue is, as I found complaints on nearly all the rebuilders of size that I could find. The best, I think, based on reputation and their description of their rebuild procedures on the website is likely to be Redhead, and even they showed up in some problems. I think that even with Redhead I would send them my gear to be rebuilt rather than take a ready to ship unit, as then I would be sure I got the same ratio and effort valving. Finding a local shop that will rebuild your gear, and does a complete check of parts and full wear item replacement, might be another option. A place that blueprints gears for the offroad or racing crowd might be a place to start, but won't be inexpensive.


My Buick update was supposed to be done this winter when I have lots of time, but got moved up when it developed a major power steering leak this week. Luckily, I had already found a source for what I needed at a high end rebuild/custom rebuilder in California (Lee Power Steering) and one of their "near off the shelf" gears with a matched, blueprinted, reverse flow (needed for the odd LT1 engine setup) blueprinted pump is what they recommended and did sound like just what I would have chosen. With essentially no experience in a wide range of speced setups, it was very hard to chose what will be best for the feel I like, the weight of the Buick, tire size, etc. They got the stuff out in a day after I called, so we will see how it goes when they get here and I get them in the car. They claim to replace all seals, bearings, the recirc balls, bushings, etc and do a complete hydraulic test to measure steering effort, side to side balance, centering, backlash, etc. Lee would be an option for anyone with a Chevy van, I think, as they do all the older versions and the hydroboost ones, but they will be the most expensive.
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Old 10-26-2018, 08:24 PM   #2
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Interesting story. I look forward to hearing about the results.
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Old 10-26-2018, 09:30 PM   #3
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Booster,
When we got our 1999 Xplorer the steering was horrible. New ball joints & tie rod ends helped but still was bad. Tried a couple of alignments to my own spec (I like lots of castor and a little negative camber when trying to get something to go straight) and it was better but still not there.

More research led me to Red Head (they seem to be well regarded in the off road community) and they are about 60 miles from me. I chose to have mine rebuilt rather than one off the shelf, for the same reasons you outlined. Vast improvement but I thought the preload was a little light because the van still had more wander than I would like, admittedly, am quite picky.

This part may not be important to your Buick but the one thing that I kept seeing was the flex (for want of a better description) or deflection of the pitman shaft and arm when changing directions. Like most all steering boxes, the pitman shaft is operating in single shear and there is enough clearance in the bearings to allow a fair amount of movement which translates to slop in the steering.

Then I discovered this steering box stabilizer Dodge Ram Steering Gear Box Stabilizer
It's basically a shaft extension and a bearing mount which puts the shaft in a crude double shear and therefore a much more stable shaft centerline causing much less slop. This steering stabilizer made a new vehicle out of our van (and a nicely cheap fix). I doubt your Buick has the handling problems of the Dodge vans, so the stabilizer is probably not needed in your case but I thought I would mention it in case you have 'wandering' issues.

Will also be looking forward to results.
Dave
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Old 10-26-2018, 10:02 PM   #4
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D&J, I am actually familiar with the Dodge stabilizer bar from the numerous times folks have chased the handling issues on the Dodges. From what I understand, it does, as you say add outboard support to take the cantilever out of the pitman arm shaft and bottom bearing, and it also ties that outer support back to the van frame to eliminate the mounting flex in the entire gear where it hooks to the frame. Everything I have heard supports what you say about the big difference in steering response, especially at tip in where the initial movement would be. The Chevy and Buick frame mount is very sturdy, as is the box itself, so the mount flex isn't there, and the bottom bearing seems to be very tight on them. I haven't heard of any reinforcing done on them except for extreme offroad stuff in non vans. I opt for better directional stability over max cornering in big heavy street vehicles.


I am a bit surprised that the Dodge does better for directional stability with a small amount of negative camber, as it is usually a little positive that helps that. Negative will usually be better for holding in turns, though, and positive not as good there. Our Chevy Roadtrek and the Buick both like a about 1/8-1/4* of positive camber with as much positive caster as they can get.
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Old 11-01-2018, 05:27 PM   #5
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Quote:
Originally Posted by booster View Post
D&J, I am actually familiar with the Dodge stabilizer bar from the numerous times folks have chased the handling issues on the Dodges. From what I understand, it does, as you say add outboard support to take the cantilever out of the pitman arm shaft and bottom bearing, and it also ties that outer support back to the van frame to eliminate the mounting flex in the entire gear where it hooks to the frame. Everything I have heard supports what you say about the big difference in steering response, especially at tip in where the initial movement would be. The Chevy and Buick frame mount is very sturdy, as is the box itself, so the mount flex isn't there, and the bottom bearing seems to be very tight on them. I haven't heard of any reinforcing done on them except for extreme offroad stuff in non vans. I opt for better directional stability over max cornering in big heavy street vehicles.


I am a bit surprised that the Dodge does better for directional stability with a small amount of negative camber, as it is usually a little positive that helps that. Negative will usually be better for holding in turns, though, and positive not as good there. Our Chevy Roadtrek and the Buick both like a about 1/8-1/4* of positive camber with as much positive caster as they can get.
You are talking about making what is considered a boat, handle better wow! Buy a BMW wagon if you want something to handle better. Definately not a Roadmaster.
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Old 11-01-2018, 06:57 PM   #6
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Booster,
Good post.
I have two Roadtrek 190 s, one 220,000 miles with new steering and suspension components except steering gear box and another with 22,000 miles. The newer RT has better handling so replacing the gear box has been churning around in my mind for the high mileage RT.
Your post triggered valuable follow-up posts.
Thanks to all.
This is a particularly good thread.
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Old 11-01-2018, 09:27 PM   #7
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Originally Posted by Scottie409 View Post
You are talking about making what is considered a boat, handle better wow! Buy a BMW wagon if you want something to handle better. Definately not a Roadmaster.

Maybe, but I culd put that BMW wagon inside and haul it around in the Buick Pluss the Buick probably cost less than 5% of the cost of the BMW, I got the Roadmaster as my retirement car as I was sick of compacts and compact wagons even as they can't haul anything of consequence. Now I can haul about the same as Suburban can, and more than pickups unless they have the now rare 8' box. We had a "pro touring" turbocharged 1970 Challenger for 25 years, so had plenty of that kind of fun.



Most folks don't realize the Roadmaster is the "geezerd up" version of the Chevy Caprice, which in cop form was one of the all time favorites of nearly every cop I have ever talked to as they really liked how they drove when pushed. They are also the same car as the Impala SS of that vintage and they all have the same engine as the police got from '94-'96. The basic design is quite good, front engine, rear drive, double A arm front, trailing arm coil spring rear. Firm the suspension a bit, add rear swaybar, and a steering gear with some decent feel and you are good to go autocrossing, which believe it or not a lot of people do both with the wagons and the sedans. Where else can you get a muscle car with woodgrain ?!?
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Old 01-17-2019, 04:51 PM   #8
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Stumbled across this thread when looking for something else and figured I would update how the old Buick actually turned out after all was said and done.


The job got crazy long as the clearance to change the gear and pump are tight and a lot of parts had to be removed, including draining all the water. Add to that the fact that when I got it all back and running, the water pump blew out the rear seal and bearing, and dumped water all over the very fragile Optspark distributor right below it. This a the GM reverse flow setup, so weird pump that required the entire front of the engine to come off down to the timing cover, including the damper pully. Optispark cleaned, sealed, etc and reinstalled. All good now.


As for the handling, with the new gear it was tight and straight, but a bit slow on return. Lee sets their gear quite tight, so not all the unexpected and it will get better over time. It also still had less centering feel than I like, which was also expected because the caster was only in the mid 2* range and out of adjustment.


I finally decided to get more caster, and removed the upper control arms and cut them apart to move the bushing locations, and then welded them back together. We are talking moving the bushings over 3/8", one in and one out, on each upper arm. I made fixtures before cutting, so I could duplicate the existing location but with the adjusters set to allow more adjustment off of that baseline.


Got it aligned a little while ago and now have about 6* caster on it, with adjustment still left, so in good shape. It drives very, very, much better and it did help the return speed. Good response, no feel changes as wheels turn (which it had a bit of with low caster), excellent feel and effort.


Very happy with the results to this point, and it also helped to understand just how much difference a few degrees of caster and a nice tight gear can make.
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