Differential swap time?
 

I'm trying to find out roughly how long it takes to pull the differential and half shafts out of the car and put in a replacement. Planning on swapping on Saturday and need a time estimate to give my buddy who may let me use his shop, but I have no idea. Actually, I'm taking the 1.8 diff out of one car and the 1.6 diff out of mine and we are trading so I'll take whatever time you guys say it normally takes and double it.
Thanks
-Ryan

The first time I took mine out, with help from a friend, it took maybe 3 hours. The worse part, which Im sure most will agree, is unbolting the PPF from the diff. Mostly everything else was as easy as unbolting. The other thing that gave me an issue was pushing the halfshafts out of the brak holder piece thingys. Please excuse my jargon.

After everything is out, putting it back in goes much faster! Also taking it out again goes alot faster too because all the bolts are unrusted the second time around

took me 3 hours to pull my stock 1.6 diff and put a 1.8 torsen in. If i were to do it again i could probably do it in an hr since i know what needs to come out and the order ect.

miata.net doesn't have a write-up on a swap for me to actually visualize all of the necessary steps.. too bad I don't have someone who has done one handy lol

Hopefully you have an impact wrench to bust loose the PPF bolts at the diff. Either way hit it with some penetrant before you pull it out. Some may disagree but I found that dropping the PPF with the diff, then separating the two out of the car, is easier.

Hell, can you just swap the PPFs with the diffs? If they are the same that would be a big time saver. Just unbolt them at the transmission and leave them attached to the diff. I am not sure if they are the same or not.

I would say you can knock it out in 4-6 hours tops for both assuming you have all the tools you need and you are not replacing the diff bushings. Be real careful when pulling/stabbing the halfshafts out of the diff since it is easy to tear the shaft seals with the snap rings.

What size is the bolts for the PPF to diff?

If I understand it correctly, I basically can just undo the top outer control arm bolt and the control arms will move out of the way enough that the half shafts can come out of the hubs and then just unbolt the diff from the PPF and car and remove... I'm probably missing 50 little things that I don't know about...

I may have to do this on the pavement at my apt because 4-6 hours may be a bit too long for the shop use..

Ryan, i dont know what year your pulling the 1.8 diff out of but if its a type 2 and you have a type 1 then you will need to swap half shafts too. So you will need a 32mm socket to pop those off as well.

Edit: I am a dumb ass if you have a 1.6 rear end you need to swap everything. So you will still need that 32mm socket to get the halfshaft out of the hub.

Good god thats huge. Ok, he's got a 32 I can use. What about the PPF bolts?

They are 17mm bolts, easy with a breaker bar. Remove the two at the diff, the rear 2 on the tranny, and loosen the front one on the tranny so the PPF will swing out of the way. Drop your exhaust. Loosen the 14mm nuts on the driveshaft and halfshafts. Two 12mm nuts and a 14mm nut drop the mount cups and mounts out, and then you bench the diff down and out of the car. E-brake, stand on the brakes, 32mm with a breaker bar to break the nuts loose. If you're lucky, they'll come out with a couple taps of the hammer. Reinstall new halfshafts, new driveshaft, bench diff into place, repeat.

My roommate and I can drop a diff and install a different one in 25 minutes. Full Torsen swap would be around an hour. 4-6 hours is a good estimate if you have trouble with the halfshafts.

~3 hours. Hardest part was getting those half shafts into the diff without destroying them.

it all depends on wether the halfshafts are seized like mine where if they are not seized and you are competent then u can do it in 2-3 hrs on jack stands. If they are seized then pressing them out takes more time.

do poly bushings now, thank me later.

+ 1, MMR bushings are boss

does doing the bushings for the diff require burning out or pressing out the old and pressing in the new like any other bushing? I suppose I could, I was eyeing full bushing kits and thought about getting the diff bushings along with but hadn't thought much of it.. if I'm at/near the shop where there's a press I guess that wouldn't add tooo much extra time.

Was looking at a site that had a nice full bushing kit + diff bushing for a good price on some site and now I can't find it. I found a GREAT price for full suspension bushings kit from 949 Racing but they are sold out of the Energy Suspension diff bushings until April 10 and I'm looking at doing this this weekend maybe. Does anyone have a good recommendation on a different affordable diff bushing from a certain place or the same ones for sale somewhere else at a good price?
MMR has them for $50 which is a great price.. I've heard he takes a while to get them out sometimes though? Maybe I will call tomorrow to order some from them if they say they can get them here fast.

-Ryan

Ryan, I just installed Energy suspension
bushing master kit and it took longer than I expected! Getting the bushing out of diff is a PITA if you don't have proper tools. A-arm press!

it all depends if the bolts and nuts come apart without fighting. Prolly 3 hours is a good estimate even tho it can take more. For example I did diff bushings, new axle seals, painted stuff.

I just installed Energy Suspension polyurethane bushings without a press or any special tools. A press would be nice but not necessary.

Press is not necessary....drill holes in the rubber mounts in a circular pattern. When the center comes out, with some lube they can be extracted or heated and extracted. I've even had to resort to tamping one out with a chisel and 3 lb. hammer.
Clean.....clean....clean.
No better time than now with these many parts coming apart, and it will pay off with looks for sure.
Wags and I swapped two in one afternoon in two different cars in about 5 hours. That's even to go get Poly bushings after my Delron's didn't fit right.
First time for us then, and can easily be done quicker next time.

That is exactly what I did. Drill out the center portion, pound it out with a chisel and a small sledge hammer. The outer steel portion of the bushing is in two pieces; you can see the seam if you look closely. If you hit one side of the steel shell with the chisel close to the seam it comes out easier. You have to hit it pretty hard at first so be sure to put a block or something under the end of the housing leg so you do not bust it.

Thanks for all the input guys. I just ordered MMR differential bushings. I wanted to call them and ask about an ETA but they have no phone number on the website just email, so I went ahead and ordered the bushings. Once the order went through paypal, paypal showed me a phone number for MMR so I called but it went to a cell phone voicemail box.. so, I left a message and hope they can bust these out quickly. Seems a bit sketchy but others run these bushings so I think they are trustworthy and the product seems to be good. Can't beat the price either.
-Ryan