My 99 got rearended in the last race of the season. Everything looked cosmetic until I got the exhaust out of the way and found this mess. I think the subframe damage is just cosmetic. What can I do to save this diff--its the original with only 15k miles?
-------------------- Kyle Burkhardt NASA Midwest #12 SM
Region: atl
Car #: 10
Year : 95 Posts: 31
Status: Offline
posted
The diff is a pretty easy fix, v-notch around the crack and have a good welder tig it back together. Small reinforcment plates can be welded into the hollowed out area to strengthen the welded area.
Region: mid south
Car #: 2
Year : 1999 Posts: 4275
Status: Offline
posted
We have diff housings and subframes, they are relatively inexpensive. It is not "legal" to brace the diff housing, but it would be a weeny protest. By the time you pay to have welded you can have a complete used one.
Region: mid south
Car #: 2
Year : 1999 Posts: 4275
Status: Offline
posted
The case is very simple. Just unbolt the bolts around the perimeter, use a bead of silcone on the replacemnet and it drops in. Typically the force does not bend subframe, but I see yours is bent in the picture by the sway bar.
Region: chicago
Car #: 72 and ?
Year : 90 and 90 Posts: 1051
Status: Offline
posted
Before attacking the diff, I would check the subframe for bends. No sense in pulling the diff to replace the housing, only to have a bent subframe that will require pulling the diff a second time.
I sell an inexpensive tool for checking the rear subframe for bends.
Sway bars very rarely get damaged, but subframe bend regularly.
Dave
-------------------- Advanced Autosports, The Midwests leader in Spec Miata Service, Parts and Rentals 608-313-1230 Authorised Spec Miata service center www.advanced-autosports.com
If I transfer to the diff to the new housing, does that require any kind of adjument or reassembly, or does it just all come out of one and into the other together?
-------------------- Kyle Burkhardt NASA Midwest #12 SM
Region: So Cal
Year : 90 Posts: 74
Status: Offline
posted
Miata.net has some good tutorials. A swap isn't difficult with moderate mechanical ability. It's the gear change that's tough if you've never done it but if it's a straight swap you won't be taking the pumpkin apart. A big +1 on taking the rest of the subframe down before swapping the diff. If it cracked the diff like that and bent those other members there is a pretty good chance other parts are askew.
On edit, wrong link posted. It was the pinion swap and you don't want to try that alone the first time if you can help it.
Link to tutorial page where you might find something...
Thanks. I've been looking around miata.net and found what I need. Gonna get the diff down and then reevaluate. I think what happened is the car that hit me got a good shot on the exhaust and that worked as a lever to snap the diff.
-------------------- Kyle Burkhardt NASA Midwest #12 SM
Region: NER
Car #: 7
Year : 1999 Posts: 636
Status: Offline
posted
You should be able to remove the broken rear housing and bolt on a good one pretty quickly. No gear adjustment/shimming required. That notch in the ear of the aluminum rear housing is designed to break exactly where yours did. We went through 3-4 of them last season during soft to hard rear hits. All were welded back together and sit in reserve as spares.
-------------------- -Cy Supported by LTD Racing & Speed Shack - New England's Premier Auto Accessory Store Rt1 AutoMile - Norwood, MA http://www.speedshackonline.com