[02341360]

Leading on from here Is ABS worth swapping in? I am going ahead installing ABS on my 1993 mr2 (using JDM years, USDM are + 1 year I believe). I have parts left over from my crashed 1991 mr2 that did have ABS. I have a 2005 mr-s combined ABS pump/ECU unit coming over from Japan which I am praying comes with the pigtail loom in the picture. Engine / fuel tank currently out as I am swapping them over from my old car (were freshly rebuilt).

I took the central brake line from the 1991 car when I dismantled it. The 1993 has a single brake line of course and a clutch line but also an empty row in each bracket that screams chuck a 2nd brake line in me... ok. The identical line from the 1991 fits almost perfectly. It needs a touch massaging over a couple of spots. I also took out the galvanized fitting on the front "firewall" that both the brake line and clutch line screw into cut the bracket down to size and bolted it up.

My main problem is working out the knuckles. The 1991 knuckles have the smaller brake shields and I am the sort of idiot who has to have them perfectly intact and matching. My idea is:

Rears- there appears to only be two part numbers 42304-17010 and 42304-17020 for all mr2's 1989-99 which I assume is just ABS and non-ABS knuckles. So I think it makes sense to swap the 1991 ABS knuckles over to the 1993 but have them pulled apart and swap the 1993 dust shields over and might as well replace the wheel bearing for fun. Anything else worth replacing on them- I see there is a non-reuseable snap ring and the dust shield might be a bit worse for wear? I assume you can't change the brake dust shields without dismantling the hubs?

Fronts- there are at least 7 still available part numbers (I am guessing apart from the years, also ABS and power / non-power steering options). Apparently the steering geometry changed from 89-91 to 92-93 to 94-95 and 96+ and also some overlapping parts. My idea is to buy new 93 ABS knuckles 43211-17100 right, 43212-17100 left (I have no idea if 96 would be better), new wheel bearings also and swap all the other parts from the 1993 non ABS knuckles/hub over. Obviously not the cheapest option but I don't mind buying new vs hunting around dozens of scrap yards for relatively rare parts.

Does this make sense or am I missing something major?

 

[Alex W]

That's pretty cool that the car has the triple line clamps already in it. Makes it easier for sure.

Can you even buy new knuckles anymore? I just looked up the part numbers, and they appear to be discontinued, based on google searching the part number. Even if they are available from the dealer, might I suggest these, for a similar price? Aluminum Knuckles
Granted, there are additional parts needed to install them, and I realize they may not suite your goals for the car.

I don't know about 7 different front knuckle part numbers for what additional variations there may be, but for sure I am aware of ABS / No ABS, and power steering / manual steering. What the other variations may be, I'm not sure. Maybe they took steps in the later years to address the ultra low roll center that you get with the stock 91 geometry?

 

[02341360]

I did consider your kit, it looks amazing but I think the cost will be much higher with the extras and currency conversion, international shipping etc. My main concern is also that I doubt our safety inspectors will be very enthusiastic about it. They routinely fail the wilwood kits for the handbrake brackets. I'll keep it as a backup plan.

Yes they are showing a couple of part numbers discontinued from Japan. Most others show stock ie >1 but there is plenty of scope for it to not work out. Here they all are, I am guessing there are four different knuckles- ABS, PS, ABS + PS and neither option for all year groups. I am guessing the later models only came with ABS hence not having that mentioned.

My 1991 had manual steering (93 has PS) so I will need to source something regardless.

 

[JimKing]

My recollection is that 1/92 builds (93+ USDM model year) front knuckles received larger bearings for "more positive steering feel". So front wheel bearing part number should change there.

And yeah, when I did this Spyder ABS thing on my 91 many years ago, I also noticed that Toyota was already thinking about a 4-channel system, since the 3-position clips were already there.

 

[tabKola]

According to the new car features for US 94 this is what changed. The bearing and the hub are the same part number for all years so the change must be in the knuckle.

 

[02341360]

I know Phill said in the previous thread, the knuckle steering arm length is different for the different year groupings. Wheel bearings are the same part number from 89-99. I'll post back with how I managed to get on with this. I imagine the wiring will be the challenging part. I have the old abs sensors sprayed with a bit of wd40 for a week hoping they will come out in one piece.

 

[JimKing]

Ah so, the bearing itself didn't change. And one of the "improvements" was in the strut top.

 

[Alex W]

The HUB changed in 93 or maybe 94. It got a thicker section around the joint between the flange and the stub that inserts into the bearing, making them a bit stronger.

Another option would be to just machine the knuckles you have to fit the ABS sensor. Depending on actual availability of the knuckles. Especially if you have a set of ABS knuckles already to use as an example.

 

[SixAppeal]

Seems these retrofits are coming up a lot lately. MR2 Spyder frunk harnesses are had to find these days. So, I've bought a frunk harness and abs pump for a 99 SW20 from Japan. It uses a similar abs pump to the 01- 02 Spyders and should be a lot simpler install since its the same platform.

Also, I think may have bought the last pair of rear abs knuckles a back in 2019. The fronts were already discontinued so I got a used pair from Japan off ebay.

 

[02341360]

Seems these retrofits are coming up a lot lately. MR2 Spyder frunk harnesses are had to find these days. So, I've bought a frunk harness and abs pump for a 99 SW20 from Japan. It uses a similar abs pump to the 01- 02 Spyders and should be a lot simpler install since its the same platform.

Also, I think may have bought the last pair of rear abs knuckles a back in 2019. The fronts were already discontinued so I got a used pair from Japan off ebay.

I put my order in for front knuckles last night. Site said there was 1+ stock, they are usually quite accurate but I have had things cancelled before, often within a week if there isn't stock after all so I will find out, I am not especially hopeful. I ordered 4321117100 (right) and 4321217100 (left). My ABS unit arrived, it came with the loom!!! Being a combined pump/ECU unit it should make wiring easier. I have almost my entire 1991 wiring so hopefully that will be enough to make a harness. I haven't explored the wiring yet but I am hoping there is minimal integration with the existing car systems required other than power, igntion, ground etc. I will have to figure out where the left rear ABS sensor wires go since it seems all cars came with that. The right rear sensor loom from the old car should be a piece of cake to install.

The HUB changed in 93 or maybe 94. It got a thicker section around the joint between the flange and the stub that inserts into the bearing, making them a bit stronger.

Another option would be to just machine the knuckles you have to fit the ABS sensor. Depending on actual availability of the knuckles. Especially if you have a set of ABS knuckles already to use as an example.

This will be my plan C. I have yet to pull the ABS front knuckle apart, I don't know exactly what changes were made to fit the metal "sensor ring" inside. As I will be a while away from actually completing this I will keep an eye out for wrecked later model cars if the new knuckles falls through. In the meantime, next week I will take the rear ABS and non-ABS knuckle/hubs to have the brake dust shields swapped and they can replace the wheel bearings and anything else that needs doing.