I did this job a while back and intended on documenting my experiences for any future reference via the search function. Unfortunately I got super busy with work and enjoying the results of my labor so I never got a chance to make this post. I will attempt to keep this keyword rich so it will get hits for others after the same info I looked for. I ran into a couple suprises that I did not get info on before I started the project. Even with the problems I managed to get the car back on the road in 2 days. Hopefully any new info I provide will be added to the tech section by the moderators!

First of all I am working on a '72 1200 coupe. It had the original H145 rear in it and 4 spd trans. I picked up an H150 rear end from a late 70's B210 with a 3.7 ratio, which I was happy about because I was after longer legs for the freeway. The 60A came from an '81 210 (B310) which is still in my driveway awaiting time to butcher the rest of the tasty meat and dispose the corpse.

What prompted the weekend from hell was the fact that every single bearing in the poor old 4 speed was begging LOUDLY to be retired, and original H145 rear was also loud. Besides that the car was just too short legged for my interstate commute and I really needed to do somthing about it.

On to the technical details of the project. I started by dropping the 4 speed trans and laying it to rest in a dark corner of the shop. I supported the rear of the engine with a jack stand and lifted the 60A into place for the first time. I had read in the tech section that the reverse sensor would interfere with the mounts for the old tranny in the tunnel and this did turn out to be the case. I had already removed the sensor and cut off everything extending above the hex bolt portion (filled the hole with epoxy) but it was not enough to make the clearance. I pulled the remaining nub of the sensor back out and cut it half-again shorter and re-installed it. When I re-fitted the transmission it was STILL not short enough to clear the tunnel mounts and this was my first oh-crap moment.

Lesson 1: Just remove the sensor, clean the hole well with alcahol and epoxy it shut taking care not to let it run into the transmission. My final solution was to shave the sensor nub as thin as possible while still retaining enough meat to seat it in the threads. In the end I cut a notch out of the tunnel mounts to make clearance for the reverse sensor on the 60A. This worked but it would probably be easier to just take the sensor out and plug the hole.

After I was able to get the transmission in the proper position I went to build the deceivingly simple mount shown in the tech section. I did'nt get very far because I realised right away that the mount shown in the article used the B310 rear transmission mount and vibration insulator - the one on my B310 was totally shot and the rubber was severed completely in two. I sat staring at my stock 56A 4spd rear mount for quite a while. It was was my only option without waiting, and waiting was not an option. I ended up slotting the holes in the 56A rear mount to adapt to the 60A bolt locations in order to bolt the old mount to the 5spd. I cut the crossmember on either side of the rubber insulator and made vertical fin type deals out of .125" plate to raise them to the proper level to bolt to the original tunnel mounts. I will not call this a lesson as it was particular to my situation - I am really just bragging at this point. I will post picture of the solution next time I have the trans out.

After the mount was fitted the transmission was done. The clutch slave bolted right on and all was well.

On to the B210 H150 rear end swap (day 2).

Removing the H145 rear was straight forward, once I figured out how the shackles came apart. Just carefully drive the bolts out of the chassis side of the swivel and the springs will drop with the rear in tow. It was simple to remove the U bolts and seperate the rear from the springpacks. Don't forget to disconnect the brake lines and the e-brake cable before you yank on it (oops).

I slid the H150 up on the springpacks which were hanging by their front mounts. The mount seats were in the right place and everything was great. No modification was necessary, or so I thought. I grabbed the B210 U bolts and rubber bumpers and fitted them in place. Unfortunately this was when I ran into lesson 2 of this project.

Lesson 2: The H150 has larger diameter axle housings then the H145 which means you can not use the H145 U bolts to attach it to the spring packs. Problem is the B210 spring packs are apparently about 1" thicker then the 1200 spring packs, thus the U bolts are about 1" too long when you mount the B210 rear to the 1200 springs using the B210 U bolts. Dimensionally everything else was great, just the U bolts were too long. At this point I stared at the mount seats and the U bolts for a bit and decided the solution was to make myself 1" spacers between the mount seats and the spring packs to allow the U bolts to mount properly. These spacers are pretty much just lowering blocks, but I will call them spacers because lowering blocks are the wrong way to drop the rear of your car and I refuse to support that activity. I took the rear out again at this point. I had to make 4 short sections of 1" square tube with holes drilled in them matching the U bolt span front to back. I welded them on !!!with the U bolts in place!!! to ensure proper alignment. Besides the fire that ensued it worked perfectly. As with the transmission mount - I will post pictures for reference next time I am under the car.

With the spacers in place I re-fitted the rear onto the springpacks and this time the bolts were just the right length to allow me to tighten them securely. Make sure to align the bolt in the center of the pack with the thru-hole in the bottom of the mount seat. A crooked mounted rear end is no good for anyone even if it is a 3.7:1 H150.

With the rear mounted to the springs and the spring shackles re-attahed to the chassis everything was in place. I grabbed my original driveline and stuck it in the rear splines of the 60A. It DID fit even though the design of the dust protection doohicky was different. Unfortunately when I went to bolt it to the H150 diff I realised the bolt pattern was totally wrong.

Lesson 3: The 1200 driveline will fit the 60A at the transmission end but will not mount to an H150 diff at the diff end. The bolts are in a rectangular pattern while the H150 flange is a square pattern. At this point I got a sinking feeling. "Will the B310 driveline fit the H150 diff?" I crossed my fingers and bummed a ride home to grab the driveline from the B310 donor car. I smoked a few cigarettes looking at the two drive lines next to each other, drank a beer.. and crawled under the car. Sure enough the B310 driveline does mount to the H150 - I later discovered this is because the center in the B310 is the same as the one in the B210 (H150) but at that time I did not know that so it did not take away from the drama of the moment.

With the driveline in place I proceeded to hooking up the brake lines and e-brake cable. As these assemblies are almost identical to the original rear end there were no problems.

Lesson 4: No worries on the e-brake assembly or the brake lines for a stock H145 to H150 swap.

That was pretty much the end of the process, besides squeezing under the car and pumping on the hypoid bottles for an hour getting the new trans and diff topped off with oil.

To sum up without all the fluff and puff:

1. You will have to create a custom mount for the rear of the 60A in the 1200 tunnel. The mounting surface is lower and farther back than the stock 56A so neither the 56A mount or the donor mount will work.

2. You will have to get rid of the reverse switch on the 60A and probably cut a notch in the right side tunnel mount on the 1200 to fit the trans in the tunnel.

3. Stock 1200 hydraulic clutch slave cylinder fits and functions for the 60A.

4. Drive line splines on 56A and 60A match but the dust protection solutions are different. Because half of the protection is on the drive line and the other half on the transmission if you mix the two you will not have dust protection.

5. H150 has larger diameter axle housings then H145 so you cannot reuse the H145 U bolts. The B210 donor U bolts were too long so a 1" spacer (lowering block) was required to make it work.

6. Wheel cylinder bores, brake lines, and e-brake hookups are good to go with the 1200 stock to late model B210 H150 rear end swap. The drums interchange as well although the pads and mechanisms of the brakes are different.

The end result was a GREAT feeling car. I was afraid the big ratio change with the transmission and the rear end would steal the car's thunder but it really did not. This car has a strong running A14 in it and it ended up with a beautiful balance. I turn about 3500 at 70MPH on the freeway in 5th and it is a joy. First is much much longer legged and of course there is a 5th for cruising. It feels totally natural and I am extremely pleased with the new feel.

Problems: The new (used) transmission has bad syncros in 2nd and 3rd (doh!) and the B210 H150 rear I swapped in is WAY louder then the H145 I took out (DOH!).

Mistakes: My notch in the right side tunnel mount to clear the reverse switch was not quite extensive enough. At low idle the trans vibrates against the tunnel. Very annoying. Make sure you get it right - the vibration is amplified by the entire unibody and just bugs the living daylights out of me. I usually hold the idle at 2k or so when I am at stop lights just so I dont have to listen to it (or feel it as the case may be).

By the time I was getting near the end I wanted to dump the car and buy a late-model import and never open the hood again. But in the end it took only a couple days on the freeway to make it feel totally worth it.

I hope it was an entertaining read and I hope I added something to the communal knowledge base that keeps these little beasts alive and kicking!

Thanks,
-david

great read it's good to hear all the intricate details that are overlooked or poorly descibed and the ways around problems that are encounted

So the B210 axle, drum to drum, is the same width as the 1200?
That's cool.
Nice article by the way.
Sorry about the trans mount pic. I know one of them is mine and I think I failed to metion the rubber mount is from the 5spd.
angelo

ps- this reads like you're an American but can you update your profile with your location.

Profile is updated - quite american indeed.

Yes, the B210 H150 was identical to the H145 I took out except the diameter of the axle housings and the overall size of the center.

Interestingly, you could have saved yourself some grief with the rear end by buying two new H145/150 gaskets [yes, they are the same] & using one as a template to make a 2mm thick spacer plate.
Just remove the H145 differential, then fit new gasket-spacer-gasket & H150 diff to the original rear axle housing & you're done. No need to remove the rear axle assembly at all.

Does anyone know if the uni joint is the same for B110 & B310 are the same?
This will be a big help to me if they are as I plan to fit an H150 into my 1000's rear axle housing & just switching to the H150 drive yoke at the rear uni will help a lot.

Yes, I've added a link to this account in the 5-speed Overview article under "swap tips".

Please post a pic of your mount, the slotted idea sounds valid to me.

For the reverse light switch, I unscrewed it and screwed in a standard plug.

The transmission mount I used is the B310 one. The same one is used with 4-speed and 5-speed models (there are pics of the various kinds in the Article).

B210s with A14s used the H150, but other B210s (USA and otherwise) used the H145. This and driveshaft details are in the
Diff tech section article.

Dman, yes I think the B310 ujoints are the same, but most (all?) are glued in. Sometimes it is difficult to remove ujoints.

Quote: It's all good.
I sourced a tailshaft from a B310 Sunny Sportswagon [A14/ 60 series/ H150] & compared it to my original 1000 tail shaft. The length overall is so close to being identical that three of us couldn't pick it. The slip yoke should fit my 56A trans & the rear flange will fit my H150 differential.
The best part is that the driveshaft had a sticker on it saying that it had been serviced by a driveshaft specialist in a nearby city & a quick inspection showed that new, replaceable uni joints had been fitted. The uni joints in my original 1000 shaft are MUCH smaller.

It was recovered from a wagon that had been loaded onto a truck that was on it's way to a scrap merchant some months back. A few bucks change hands,... the driver offloaded it around the corner at a local storage yard & it has been donating parts ever since.
The gutted shell went for scrap today.