harleybutter

iTrader: (34)

Has anyone on this board swapped out their ring and pinion set? Would like to know the difficulty level, special tools required. What rear end you did the work on, what ring & pinion ratio you were at and which one you swapped to. The deal breaker question, would you do this again or would you have someone do the swap?
Debating a 3.63, just not sure how involved the swap is. Changing out internals is a totally different ball game from just swapping center section assemblies.

icantthink4155

iTrader: (12)

I havnt done it but I have had two diffs apart, I think the hardest part would be taking the diff out of the car and putting it back.

bryantaylor

iTrader: (5)

you need some special guages. i would personally just take it out of the car and take it to a performance shop and have them do it. there are several measurements that need to be perfect.

KMag

iTrader: (2)

This is one of most specialized tasks you can perform on your miata. You need very special tools and you had better know the procedure or you will toast the diff and gears.

As bryan said, take it to a proven shop that has built diffs. It's not something you want to experiment on.

KMag

Ben

iTrader: (33)

I agree. There is no margin of error here. I recommend having a shop set it up.

harleybutter

iTrader: (34)

I figured as much. Thanks for the input.

sn95

iTrader: (2)

Sheesh, did I get morphed over to Miata.net???? People on this site re-build turbos, build their own Megasquirts, and tune self constructed turbo cars to put out close to 200hp/liter.

Rear ends haven't changed much in the last 50 years (look at the 9'' Ford rearend used in so many high powered drag cars...same design and basic parts as the 1957 model). To properly setup a rearend, you need to have a good manual (factory service manual for the Miata is excellent) and take the time to understand what the critical measurements are (pinion depth, pinion pre-load, ring gear backlash). When changing a ring/pinion on an existing rearend, careful inspection and measurement of key dimensions during disassembly and diligence in identifying and segregating each piece and its proper orientation (bearing caps, spacers, shims etc.) can save a lot of time and pain on the new install.

Scale of difficulty is harder than changing a clutch but easier than overhauling the stock 5 spd.

miataspeed1point6

iTrader: (1)

I'm having a shop do mine. I have never done it before. I don't like to practice on an expensive parts like a rear end.

Rishi

Are you having a shop in Detroit do it? If so, what shop?

reddroptop

iTrader: (4)

Local places around here wanted 600, OUT OF THE CAR.

**** that.

Miata.net has a good article, and I have the FSM, going to do it myself and take my time with it.

Starsky

iTrader: (1)

Are you going to be as careful as when you rolled your fenders?

sn95

iTrader: (2)

Reddroptop,

I can dig up some links to 9" Ford rebuilds (Miata is very similar in design) if you want them. Trickiest part is going to be accurately doing the pinion depth setting (I'm assuming you are NOT going to waste money on the factory SST). If you are replacing one OEM gearset with another OEM gearset, chances are pretty good that re-using the OEM pinion shim(s) on the new pinion will give you a good depth setting (this is how most shops do gears on the Ford 8.8 rear...they know factory pinions are consistent and they don't bother to do the pinion depth measurement....that's why they will quote a $100-$150 higher install price for non Ford Motorsports gears). If you are going to try and measure the pinion depth per the FSM, you are going to have to improvise a bit. If possible, try to get a ballpark pinion depth measurement on the existing setup before taking it apart.

reddroptop

iTrader: (4)

Thanks SN95, I could use all of the help I can get! You can either post them here, or I will PM you my email.

mikeflys1

iTrader: (2)

I've done a few (2 on mustangs and once on my miata)....it definitely requires more attention to detail than other things and you need the specialty tools but its not that difficult. Some tips.... dont rush, measure the beginning backlash and adjust the new gears to the same, mark the starting position of the adjustment collars and r&r them back into that position, when you move the collars move them together ie 1 spot clockwise on one side=1 spot counter-clockwise on the other.

As long as you dont make any huge mistakes, like leaving a bolt loose or leaving something inside the housing, the worst that can happen is it whines and you're out another hour to remove it and readjust.

magnamx-5

iTrader: (7)

Do you see us doing 5 speed overhauls rebuilding turbos etc is easy messing around with the exact tolerances onf pinion depth etc while not uber complicated can get furstrating and expensive to the DIY without the right tools IE dial calipers etc. And these tools can run a pretty penny sometimes. Out of the car i see no reason why a shop would charge more than 100$ to RR the RP

Gotpsi?

iTrader: (5)

you'll need a dial indiactor torque wrench. All the diffs ive done have used a .020" pinion shim for proper pinion depth, Ive never done a for 9" or miata rear, but countless eatons out of trucks and they are about the same just much bigger. Ive also done 3 camaro's, gm 14&12 bolts, and a bunch of ford 8.8s and a 7.5.

sn95

iTrader: (2)

Articles:
Good general 20 page article on rearend setup & critical measurements
http://www.selectric.org/manuals/rea...koninstman.pdf

Good article specific to 9" Ford
http://www.ford-trucks.com/article/i.../Ford_9_Inch_R
Go through this article with the Miata FSM open and you'll see the striking similarities (pinion crush sleeve, pinion shims, backlash adjustment, carrier pre-load etc.) between the Ford 9" and the Miata.

Great overview of rear end overhaul (Dana 60) with detailed explanations of pinion depth, backlash measurement, pinion bearing pre-load and carrier bearing pre-load. Includes details (very applicable to Miata 7") on how to make "assembly bearings" and how to get pinion depth correct without any special service tools.
http://www.pirate4x4.com/articles/te...sta/Gear_Setup


DVDs
Excellent 2 DVD set
http://www.badshoeproductions.com/products.html

Same DVDs for rent
http://smartflix.com/store/video/373...ord-9-Rear-End

Utube excerpt of above
http://www.youtube.com/watch?v=bSCUck4M6W4

sn95

iTrader: (2)

WTF are you going to use dial calipers for on a rear end rebuild??? Import dial indicator and stand < $25. Import 7" micrometer < $75. Torque wrench and other hand tools required should already be in your toolbox.

Go get some quotes on R&P install from a dealer and/or a real rear end shop; you'll be lucky to get the pinion seal replaced for $100!!

BTW, since when does a turbo that spins at over 100K rpm have looser tolerances (properly setup and balanced) than a 7" ring gear????????

magnamx-5

iTrader: (7)

dude all you do on a turbo rebuild is swap bearings and seals etc, then torque the clearances are in the bearings etc. 9-10 times if the tolerances are out of wack further than that we just replace the friggin turbo. You know what i mean dude so what if i called the indicator a caliper the **** needs to be measured. The links you give seem nice though.

bryantaylor

iTrader: (5)

unless you plan on doing a ton of rear ends, its cheaper to just have it done, instead of buying the tools and doing it yourself.