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TR2/3/3A Moss Steering Rack Conversion
- Thread starter mt10flyer
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TR3driver
Great Pumpkin - R.I.P
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This is more my un-experience : The R&P conversion forces you to lose the proper functioning of the control head, which seems like a dis-improvement to me. It also increases the steering ratio, meaning you have to turn the wheel farther to make the same turn. And unless carefully done, it messes up the suspension geometry even worse than it was to begin with (I have no idea how the Moss conversion is in this regard), aggravating the bump steer characteristics.
Although much maligned, I know from experience that the original Bishop steering box can work quite well if carefully rebuilt. IMO the main source of heavy steering is often overlooked : There has to be an absolute minimum of play between the rocker shaft and it's bushing. Used to be that replacement bushings were supplied slightly undersize, so you could ream them to match a worn shaft, but the last few I've bought were not. A friend of mine actually machined the box to take a second bushing above the original one, which I think is a great idea (and will try myself next time).
Although much maligned, I know from experience that the original Bishop steering box can work quite well if carefully rebuilt. IMO the main source of heavy steering is often overlooked : There has to be an absolute minimum of play between the rocker shaft and it's bushing. Used to be that replacement bushings were supplied slightly undersize, so you could ream them to match a worn shaft, but the last few I've bought were not. A friend of mine actually machined the box to take a second bushing above the original one, which I think is a great idea (and will try myself next time).
TR250Guy
Freshman Member
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When I did the restoration on my TR250 I installed one of the Moss quick racks. I know some people like them but I'm not one of them. The quicker steering is not needed, the original steering isn't exactly slow. Then there is the issue of the increased steering effort. But my biggest dislike is the fact it makes the car very sensitive to steering inputs. If your attention gets distracted and you slightly move the steering wheel during this distraction you can find yourself off the road or into oncoming traffic. In short, in my opinion, the quick rack does not benefit the driving experience...unless you auto cross. This might not apply in your case since I don't know anything about the TR3 conversion. But if its a quicker steering ratio I would try to drive a car with a quicker steering before doing this conversion.
OP
mt10flyer
Senior Member
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I find my 3 is hunting with more play than I like at speed. It is not comfortable especially with the over-steer that it already has. I am not closed to going through the existing steering, in fact I haven't really even looked at it for years. But already being there to replace the radiator, installing the rack is almost done anyway.
The rack for the TR3 is not the quick rack so I'm not too worried about that, nor the control head so much. I hadn't heard however, that it increases the steering ratio. That I'm not liking.
The rack for the TR3 is not the quick rack so I'm not too worried about that, nor the control head so much. I hadn't heard however, that it increases the steering ratio. That I'm not liking.
I had considered a R&P for my TR3 over the winter and looking around only Rimmers offered a conversion kit Moss was showing theirs as N/A. I see now they have relisted one with a price. When you add all the parts for the modification it becomes a little pricey. I heard that Rimmers was a converted Mini rack fabricated to fit. you might want to call Moss and see if theirs is new or from a Mini. Also if you can weld and fabricate brackets a friend used a TR7 rack in his Tr3 racer.
I have another friend who converted to the R&P loves it. But he also did this, changed the Trunion to the TR4 type for 3 degree Caster(?)and used modified TR6 upper suspension arms that could be adjusted for camber adjustment. The vendor he bought it from in Virginia no longer does them.
Since I recently bought a TR3 in restoration progress and the steering and suspension are done I will stay with that to see how it works.
I have another friend who converted to the R&P loves it. But he also did this, changed the Trunion to the TR4 type for 3 degree Caster(?)and used modified TR6 upper suspension arms that could be adjusted for camber adjustment. The vendor he bought it from in Virginia no longer does them.
Since I recently bought a TR3 in restoration progress and the steering and suspension are done I will stay with that to see how it works.
did not notice the change in steering ratio. Seems fine. I used a spacer and longer bolt to take care of the bump steer. In order to correct the bump steer, the end link had to drop down about 7/8 of an inch. The correction requires a lot of measurements and trial and error to finally get the correction.
Jerry
Jerry
groupdeville
Jedi Hopeful
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To add to TR3driver's post above, in conjunction with a thorough going-over (with upgrades) of the stock steering gear, you might well consider the benefits of the Revington steering-geometry kit for TR2/TR3. I've bought the kit and like the idea, but haven't installed it yet. Certainly I'm unwilling to delete the steering column and turn signal switches, as well as the engine-driven fan. Here's the Revington link, and it would be great to hear from anyone that's already used it:
https://www.revingtontr.com/product/rtr3314k/name/steering-geometry-imp-kit-tr2-3b
https://www.revingtontr.com/product/rtr3314k/name/steering-geometry-imp-kit-tr2-3b
I started out by adding Revington's suspension kit and steering geometry kit to eliminate bump steer. Then I had the original steering box rebuilt by Macy's garage. I also replaced the silent block bushing with Revington's brass bushing to reduce friction. I had new 155 radial Michelin's. Despite having a suspension that was in perfect order and a professionally restored steering box, the steering required a lot of muscle. More than my 105 pound daughter would tolerate. I switched to Revington' welded rack and pinion setup and the difference was night and day. Steering is effortless and there is no free play in the steering wheel. I have retained the original control head by using Bastuck's steering column modification, only losing the self cancelling function. With the rack and pinion steering you could also reduce the steering wheel size to a 13" or 14" steering wheel. There was no change to the steering ratio with the Revington R&P steering, although I understand there is with others.
It is probable that by correcting the steering geometry and eliminating bump steer, the steering effort was significantly increased. In addition when these cars were produced, bias ply tire were the order of the day, which had less road contact area so the steering was lighter. If I was to use the original steering box, I would also leave the steering geometry as original and maybe run bias ply tires. I have another TR3B in the process of restoration and am debating whether to modernize the steering or leave everything as original.
It is probable that by correcting the steering geometry and eliminating bump steer, the steering effort was significantly increased. In addition when these cars were produced, bias ply tire were the order of the day, which had less road contact area so the steering was lighter. If I was to use the original steering box, I would also leave the steering geometry as original and maybe run bias ply tires. I have another TR3B in the process of restoration and am debating whether to modernize the steering or leave everything as original.
TR3driver
Great Pumpkin - R.I.P
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What stops the head from turning with the wheel ?
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nothing. So, after a turn, you need to put the turn signal back to the center. You get used to it, so now it's automatic. I also got the Bastuk (German) slip ring set up which allowed me to continue to use the original head.
My set up is the Moss rack and RevingtonTR camber/caster improvements. I tried unsuccessfully to modify the rack with a short-throw rack, because I did notice the longer turning radius. But the quick throw rack was an inch too long to allow for enough threads to engage the tie rod ends safely. So, I now have an unused TR4 quick throw rack available... hint, hint.
What was the original question- And have we answered it?
Just FYI if you are going for the R&P change. A fellow club member used the Revington kit and he has bump steer also. So that issue is not dealt with on either kit. But, you get choices for the turn signals depending on which you use. I now have a MGB type turn signal on the side under the steering wheel. Not that noticeable and it works.
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Oh, the radiator... I went with an aluminum one with an electric fan. Positive earth. Neil Revington swears a harmonic damper is not needed, so none used, but I did shift to narrow belt pullies . But they're available from him or Racetorations if desired, probably elsewhere. The aluminum radiator and electric fan have worked to keep the temp at or near 165 even here in The South.
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really? If the control arms are swapped, the geometry that causes bump steer goes away. Theoretically, I guess...
TR3driver
Great Pumpkin - R.I.P
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I used to think that, too. Went over 100,000 miles with my previous motor and never had a problem. But now my TR3 is sitting with a crankshaft broken through the front web. Might just be a manufacturing defect that didn't show up for 60 years, but sure seems suspicious to me. The replacement crank will be getting a damper.
tinman58
Jedi Knight
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I just drove a TR3 with the original steering box (30,000)miles on the TR. It was a dream to drive. Very little effort to turn and straight as a arrow. If a old steering box can be rebuilt to work like the one I drove, I would remove my R&P and toss it out in the back 40 and install the original set up.
Erich72TR6
Member
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Somewhat related; I purchased a number of years ago the updated aluminum steering rack mounting clamps, I believe from moss...and found my rack would slide back and forth inside the clamps when cornering. I tightened them enough to distort the u shaped threaded rods holding them down, still no dice. I called to inquire and was told that on their test car, they had to place rubber in between the clamps and rack and also installed hose clamps on the rack next to the mounting clamps to prevent the rack from sliding back and forth... I guess the aluminum is slightly oversized or too smooth inside to hold the steering rack securely. I was told that the description of the item or design would be amended.
I would agree with Dan about skipping the R&P if the original could be made to work smoothly. My Healey has aftermarket bearing race that can be installed at the top pivot point of the kingpin which really improved the steering effort. I am sure it there was enough demand, it could be done for the TR3.
Got_All_4
Luke Skywalker
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I waited a while to respond because I was just completing the final tuning of my TR3 original steering box. Just completed a updated restoration on the car where I did some more tweaking on my box. Going back 8+ years ago (I've had the 3 since 1976) i was asking the same question you are asking. Thanks to some on the Forum and particularly Randal I stuck with the original box (like I wanted to) and with a local LBC parts supplier i was able to source a really good worm gear along with new bushings, better shimming and a new pin I couldn't believe how good the TR3 steering really could be. After the final tweaking tonight and a good 30+ mile drive my steering is better then ever. I would not even consider a RP conversion now and with the proper ride quality and for a fraction of the price of a swap. Good luck on whatever you decide.