FB Steering Box into SA; will it blend?
06-30-17, 04:10 PM
#1
FB Steering Box into SA; will it blend?
Hey, guys;
Searched but came up with nothing...
I was able to get a very good condition FB steering box recently, and I'm wondering if it will fit into my 80. I'd like to have the added adjustibility of the later design, and as my currently-installed box has developed a very slow leak, I'm considering swapping instead of fixing.
In gross dimensions it looks like it will bolt up to the chassis OK, but I'm concerned about all the stock parts in the steering column fitting properly, as there is a difference in shaft shape/diameter from the column lock cam up a couple inches.
Before I re-did a lot of basic research, I thought I'd check and see if anyone else has done this previous.
Anyone? Buehler?
Searched but came up with nothing...
I was able to get a very good condition FB steering box recently, and I'm wondering if it will fit into my 80. I'd like to have the added adjustibility of the later design, and as my currently-installed box has developed a very slow leak, I'm considering swapping instead of fixing.
In gross dimensions it looks like it will bolt up to the chassis OK, but I'm concerned about all the stock parts in the steering column fitting properly, as there is a difference in shaft shape/diameter from the column lock cam up a couple inches.
Before I re-did a lot of basic research, I thought I'd check and see if anyone else has done this previous.
Anyone? Buehler?
06-30-17, 05:25 PM
#2
I'd also be interested. The 1984/1985 power steering columns have an isolation piece at the bottom of the shaft on the inside part of the firewall. Wonder if the 1980 has the same? If it does, might be able to keep the 1980 shaft and just replace the box side.
06-30-17, 11:07 PM
#3
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pretty the box will go right in, remember that the box is 79-81.5 and 81.5-85, so they used the SA box in the FB for a bit.
the column that slides over the actual turny thing that sticks out of the box might be a little different, but that would stay with the car anyways
the column that slides over the actual turny thing that sticks out of the box might be a little different, but that would stay with the car anyways
07-01-17, 07:54 AM
#4
Hey, guys;
Searched but came up with nothing...
In gross dimensions it looks like it will bolt up to the chassis OK, but I'm concerned about all the stock parts in the steering column fitting properly, as there is a difference in shaft shape/diameter from the column lock cam up a couple inches.
Searched but came up with nothing...
In gross dimensions it looks like it will bolt up to the chassis OK, but I'm concerned about all the stock parts in the steering column fitting properly, as there is a difference in shaft shape/diameter from the column lock cam up a couple inches.
I even researched the Aussie forums and found a bit of information, but nothing that led to a factual "I used an FB box on my SA and it worked" type of post. All indications are that the FB manual box will swap into an SA and bolt up to the chassis.
I am curious though DD, what exactly are the differences in the steering shaft between the FB and the SA that you mention? Is the column lock cam a different diameter? Is the slot a different dimension/depth?
For my issue, I have coughed up a good chunk of change to procure a used SA steering assembly. They are not cheap, and I am hesitant to buy an FB box and swap out the steering shaft/worm gear assembly...
07-01-17, 04:30 PM
#5
I did some detailed measuring and it appears that an FB box, without some possibly extensive work, will NOT fit in an SA with stock interior.
Main issue is that the FB input shaft is 15cm shorter than the SA, and the difference is in the lower half of the input shaft - - so even swapping the upper part above the "collapsing" junction would not directly solve the problem, if it were possible.
That's not a huge difference, but it would be enough to prevent all the column trim from fitting properly.
As far as other visible differences:
The FB box has a more easliy adjusted input shaft preload, as it uses a hex cap instead of the SA's special-spanner-tool-required slotted cover. That larger hex shape might prevent the steering shaft cover from an SA from going on all the way - I didn't have a spare cover with which to check:
FB Box:
SA Box:
The upper end of the input shaft is different: The FB has a thicker "collar" (21mm in diameter, 53mm long)above the ignition lock cam, and the cam is welded at the opposite end when compared to the SA. The SA shaft is uniformly 17mm in diameter from the cam all the way up to the taper for the steering wheel.
The distance from the top of the cam slot to the end of the shaft is the same on both units (150mm), and the taper, splines, and threaded portion for the steering wheel seem identical. The upper half of the input shafts are identical in length at 565mm.
The length difference is all in the lower half of the shaft; swapping those would require complete disassembly of the box - - even if they'd swap. Internals may be different.
FB Input:
SA Input:
The FB box uses a better internal bearing and sector shaft preload design that helps eliminate the slop that shows up with longterm wear, which is why I wanted to swap.
But it looks to me like you'd at least have to swap the upper input shafts, as well as lengthen the lower shaft on the FB box (maybe by re-drilling the collapse-pin holes higher, if there's enough meat inside the joint) to even have a chance of it working. And the shaft cover might need modification.
More than I care to take on just now. Other projects in front of it.
Main issue is that the FB input shaft is 15cm shorter than the SA, and the difference is in the lower half of the input shaft - - so even swapping the upper part above the "collapsing" junction would not directly solve the problem, if it were possible.
That's not a huge difference, but it would be enough to prevent all the column trim from fitting properly.
As far as other visible differences:
The FB box has a more easliy adjusted input shaft preload, as it uses a hex cap instead of the SA's special-spanner-tool-required slotted cover. That larger hex shape might prevent the steering shaft cover from an SA from going on all the way - I didn't have a spare cover with which to check:
FB Box:
SA Box:
The upper end of the input shaft is different: The FB has a thicker "collar" (21mm in diameter, 53mm long)above the ignition lock cam, and the cam is welded at the opposite end when compared to the SA. The SA shaft is uniformly 17mm in diameter from the cam all the way up to the taper for the steering wheel.
The distance from the top of the cam slot to the end of the shaft is the same on both units (150mm), and the taper, splines, and threaded portion for the steering wheel seem identical. The upper half of the input shafts are identical in length at 565mm.
The length difference is all in the lower half of the shaft; swapping those would require complete disassembly of the box - - even if they'd swap. Internals may be different.
FB Input:
SA Input:
The FB box uses a better internal bearing and sector shaft preload design that helps eliminate the slop that shows up with longterm wear, which is why I wanted to swap.
But it looks to me like you'd at least have to swap the upper input shafts, as well as lengthen the lower shaft on the FB box (maybe by re-drilling the collapse-pin holes higher, if there's enough meat inside the joint) to even have a chance of it working. And the shaft cover might need modification.
More than I care to take on just now. Other projects in front of it.
Last edited by DivinDriver; 07-01-17 at 04:39 PM.
07-02-17, 05:36 AM
#7
www.AusRotary.com
You wouldn't have found anything on ausrotary using those search terms because (a) LHD is often different to RHD; and (b) we never had an FB: all our 1st gens are SAs. What you call an SA we call a series 1. What you call an FB we call a series 2 or series 3 depending on year. We never got power steering either.
I know that series 3 (84-85) steering boxes were "softer" in that they required less steering effort but as a result were also less direct and suffered worse freeplay. It is a common conversion here to swap a s2 box into a s3. I have done that very conversion.
as to a s2 box into s1, the answer is here: http://www.ausrotary.com/viewtopic.php?f=4&t=216639
I know that series 3 (84-85) steering boxes were "softer" in that they required less steering effort but as a result were also less direct and suffered worse freeplay. It is a common conversion here to swap a s2 box into a s3. I have done that very conversion.
as to a s2 box into s1, the answer is here: http://www.ausrotary.com/viewtopic.php?f=4&t=216639
Trending Topics
07-02-17, 01:13 PM
#8
You wouldn't have found anything on ausrotary using those search terms because (a) LHD is often different to RHD; and (b) we never had an FB: all our 1st gens are SAs. What you call an SA we call a series 1. What you call an FB we call a series 2 or series 3 depending on year. We never got power steering either.
I know that series 3 (84-85) steering boxes were "softer" in that they required less steering effort but as a result were also less direct and suffered worse freeplay. It is a common conversion here to swap a s2 box into a s3. I have done that very conversion.
as to a s2 box into s1, the answer is here: AusRotary.com ? View topic - S1 and S2 Rx7 steering box the same?
I know that series 3 (84-85) steering boxes were "softer" in that they required less steering effort but as a result were also less direct and suffered worse freeplay. It is a common conversion here to swap a s2 box into a s3. I have done that very conversion.
as to a s2 box into s1, the answer is here: AusRotary.com ? View topic - S1 and S2 Rx7 steering box the same?
"Changing the tube" sounds to me like changing the shaft cover, but that wouldn't seem to address the shorter shaft length.
07-02-17, 01:51 PM
#9
Old [Sch|F]ool
A P/S column is what you want if you are doing an FC steering conversion, the FC steering shaft will bolt right up to it although it will have to be lengthened a bit.
07-02-17, 01:57 PM
#10
Old [Sch|F]ool
I wonder if DivinDriver's length differences are a S2/S3 thing about an SA/FB thing. (but j9fd3s says the manual boxes are all the same '81.5-85?) One other thing I noticed about the S3 cars is that the steering wheel seemed uncomfortably further away than on my S1.
Now I gotta go out to the garage and see if my '81 has the early or late box. Making sure it's adjusted properly is next on the to-do list before the engine goes in.
07-03-17, 08:42 AM
#11
Glen, if its too short, bring both shafts to Renown in Rancho Cucamonga (not too far from you) . who knows, they made be able to come up with a better solutions than just extending the shaft. they do quality work as theyve done several FC IRS conversions on a FB as well as rotary engine work. they did the semi-pp on my Tii housings as well as many local. otherwuse, i can dig for the shop in Pomona who rebuilt a steering box for a friends FB years ago.
07-03-17, 03:48 PM
#12
Glen, if its too short, bring both shafts to Renown in Rancho Cucamonga (not too far from you) . who knows, they made be able to come up with a better solutions than just extending the shaft. they do quality work as theyve done several FC IRS conversions on a FB as well as rotary engine work. they did the semi-pp on my Tii housings as well as many local. otherwuse, i can dig for the shop in Pomona who rebuilt a steering box for a friends FB years ago.
Right at the moment, I've got the trans out, working on an upgrade to light steel flywheel and new clutch. After that, I'm deciding if to go rear disk, or just LSD & keep my drums - - picked up a 83 small-axle GSL rear recently, which needs moderate brake work before it's "go" ready.
That would explain why my S1 had excellent feeling steering while my second S3 had really shitty light feeling steering. My first S3 had power steering, I had the second one for about a month before I put the first one's box and column in it!
I wonder if DivinDriver's length differences are a S2/S3 thing about an SA/FB thing. (but j9fd3s says the manual boxes are all the same '81.5-85?) One other thing I noticed about the S3 cars is that the steering wheel seemed uncomfortably further away than on my S1.
I wonder if DivinDriver's length differences are a S2/S3 thing about an SA/FB thing. (but j9fd3s says the manual boxes are all the same '81.5-85?) One other thing I noticed about the S3 cars is that the steering wheel seemed uncomfortably further away than on my S1.
07-03-17, 07:15 PM
#13
Old [Sch|F]ool
Just an update: My '81 has a hex fastener on the input shaft like what DivinDriver posted as an FB box, but it has only two adjustments (worm preload and sector shaft height) like an SA.
Forgot to check the birthdate, but the VIN ends in 510XXX so maybe someone with fiche access can figure that one out.
It could also be that while I may have an "SA" box, there were early and late SA, since it seems like there are as many difference between '79 and '80 model year as there were between Series 1 and Series 2. And there were parts splits in the middle of 1980 so you can have an early '80 and late '80...
Also, according to Rock Auto, the A/C compressor in it is for a factory-install system, but the bracket supporting the hose to the firewall is just zipscrewed in, like it was an afterthought. Very hmm.
Forgot to check the birthdate, but the VIN ends in 510XXX so maybe someone with fiche access can figure that one out.
It could also be that while I may have an "SA" box, there were early and late SA, since it seems like there are as many difference between '79 and '80 model year as there were between Series 1 and Series 2. And there were parts splits in the middle of 1980 so you can have an early '80 and late '80...
Also, according to Rock Auto, the A/C compressor in it is for a factory-install system, but the bracket supporting the hose to the firewall is just zipscrewed in, like it was an afterthought. Very hmm.
Last edited by peejay; 07-03-17 at 07:17 PM.
07-03-17, 07:37 PM
#14
Great tip, Mel; thanks! When I get back around to messing with the steering, I will keep in mind.
Right at the moment, I've got the trans out, working on an upgrade to light steel flywheel and new clutch. After that, I'm deciding if to go rear disk, or just LSD & keep my drums - - picked up a 83 small-axle GSL rear recently, which needs moderate brake work before it's "go" ready.
I don't know the original year of the FB box I got so I don't konw if it's S2 or S3. But I can probably find out by counting lock-to-lock rotation, if it did change ratio. It's put away in the shed for now, & the bench is busy.
Right at the moment, I've got the trans out, working on an upgrade to light steel flywheel and new clutch. After that, I'm deciding if to go rear disk, or just LSD & keep my drums - - picked up a 83 small-axle GSL rear recently, which needs moderate brake work before it's "go" ready.
I don't know the original year of the FB box I got so I don't konw if it's S2 or S3. But I can probably find out by counting lock-to-lock rotation, if it did change ratio. It's put away in the shed for now, & the bench is busy.
lmk if you need help. text me aince im hardly on the forum. maybe this will give me aome motivation to work on the SA which has been on jackstands for a year now lol
07-03-17, 09:48 PM
#15
Old [Sch|F]ool
I bought it a lot more than a year ago... I don't even remember how long ago it was, the oldest images in my camera directories are from 2014 and they are from when I was moving it from here to there... I got as far as dropping the 7:1 2.3l monster engine in and that's all, the trans is still on a pallet and I haven't decided what turbo I want to use with it yet... Been having too much "fun" breaking the old RX-7 and restoring the new one and also I bought a Volvo in that time and put close to 40,000 miles on it and did a bunch of work to IT too because you can't buy something, find out that it shares a chassis with the Evo III, and NOT play with it...
Year? Pff...
Last edited by peejay; 07-03-17 at 09:52 PM.
07-03-17, 09:55 PM
#16
Old [Sch|F]ool
If Photobucket wasn't a douche, I'd be hotlinking all kinds of pics from the engine build, but Photobucket is a douche and I'm not going to pay them $400/year to host my photos when I can buy my own domain and hosting for less, eith blackjack and hookers! In fact forget about the domain and hosting!
07-06-17, 07:21 AM
#18
Waffles - hmmm good
iTrader: (1)
Speaking of hosting pics, I need to move off of google photos because they don't allow an easy way to
post pics anymore with the needed jpg or gif suffix in the url so that sites like this can show them inline.
Also need to consolidate photos from flickr and google to the new site as well. Hadn't looked at imgur
but might check it out. Was thinking of consolidating all back to flickr but am leery of how Yahoo will
fair in the near future.
post pics anymore with the needed jpg or gif suffix in the url so that sites like this can show them inline.
Also need to consolidate photos from flickr and google to the new site as well. Hadn't looked at imgur
but might check it out. Was thinking of consolidating all back to flickr but am leery of how Yahoo will
fair in the near future.
07-06-17, 08:16 AM
#19
Rotary Enthusiast
Speaking of hosting pics, I need to move off of google photos because they don't allow an easy way to
post pics anymore with the needed jpg or gif suffix in the url so that sites like this can show them inline.
Also need to consolidate photos from flickr and google to the new site as well. Hadn't looked at imgur
but might check it out. Was thinking of consolidating all back to flickr but am leery of how Yahoo will
fair in the near future.
post pics anymore with the needed jpg or gif suffix in the url so that sites like this can show them inline.
Also need to consolidate photos from flickr and google to the new site as well. Hadn't looked at imgur
but might check it out. Was thinking of consolidating all back to flickr but am leery of how Yahoo will
fair in the near future.
When I have a pic to post here, I always upload to the forum rather than post urls inline. I display the photo locally, screenshot the part I want to post, save that as "temp.jpg" and upload that file using the forum widget.
I totally get you regarding the flickr question...with Verizon picking up Yahoo at the pull-apart, you don't know what they're going to keep
.Google Drive seems to work really well for videos.
07-12-17, 08:10 AM
#20
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I need a steering box
Folks, I am new to this site and am glad to be here. I have a 1981 RX7 GSL and have terrible slop in my steering column. I have to turn the steering wheel at least a quarter turn in either direction before my wheels actually move the vehicle in the desired direction. This is very dangerous. I'd appreciate any assistance from any of you enthusiasts who can tell me where I can purchase a precise fit. I also used to experience a good deal of backfire to boot. This also led to me leaving the car sit. It has been sitting in my garage since 2012.
It's time to get it running properly. Thanks in advance for the help.
It's time to get it running properly. Thanks in advance for the help.
Hey, guys;
Searched but came up with nothing...
I was able to get a very good condition FB steering box recently, and Im wondering if it will fit into my 80. I'd like to have the added adjustibility of the later design, and as my currently-installed box has developed a very slow leak, I'm considering swapping instead of fixing.
In gross dimensions it looks like it will bolt up to the chassis OK, but I'm concerned about all the stock parts in the steering column fitting properly, as there is a difference in shaft shape/diameter from the column lock cam up a couple inches.
Before I re-did a lot of basic research, I thought I'd check and see if anyone else has done this previous.
Anyone? Buehler?
Searched but came up with nothing...
I was able to get a very good condition FB steering box recently, and Im wondering if it will fit into my 80. I'd like to have the added adjustibility of the later design, and as my currently-installed box has developed a very slow leak, I'm considering swapping instead of fixing.
In gross dimensions it looks like it will bolt up to the chassis OK, but I'm concerned about all the stock parts in the steering column fitting properly, as there is a difference in shaft shape/diameter from the column lock cam up a couple inches.
Before I re-did a lot of basic research, I thought I'd check and see if anyone else has done this previous.
Anyone? Buehler?