Quick question.. is this a MSP LSD?

[KrayzieFox]

As the title says, can anyone confirm this is really an OEM MSP differential? I had an MSP LSD lying around but had to sell it to help me with moving expenses a few year back, and I don't remember it being like this one. Something about the inside seems a bit off, is this a revised (or non-revised?) version of the OEM? Or is this what an open diff looks like?! I swear I remember the other one I had being different...

Sorry if this a noob question, just wanna make sure I bought a genuine MSP LSD and this isn't really something I have experience with. Thanks.

 

[KrayzieFox]

Anyone??

 

[Spiced MSP]

looks like one. IIRC, there were two different types of diffs made by the same company for our cars. One with springs and one without or something like that.

 

[2.0t03speed]

thats a 03.5 diff

 

[mazdaspeedp]

ya looks like a welded msp diff.

 

[BAHKACK]

What's the difference between an '03 and a '03.5 MSP LSD?
Is the 03.5 tougher?
I will have my tranny (03.5MSP)out for 3rd gear work next week.
Should I be doing anything with the diff while it's out?
Welded? Does that mean something different in the MSP world vs the miata world?

 

[malcantry]

simply put, that diff has been out before and worked on.. originally there was no weld where there obviously is now (hope you can spot the welds?!@)

that was the weak point, the diff can/will shear THERE between the housing/main gear. welding only makes THAT diff as strong as possible but is not the same/strong as an MFactory or equivalent differential.

as per 03 vs 03.5, sorry, dont know specifics for the difference.

 

[hornsfan10609]

There have been 5-6 revisions to the LSD since the first MSPs were built in 02, the 03.5s did get one of the newer versions and they did fail less often but can still break. That appears to be a true MSP diff but it's not too easy to tell from the pics. I have my stock diff in the garage if you need numbers off it to compare.

 

[Valk]

Certainly looks like my dif did.question is can you buy those ringgears by themselves? With a welded dif, it will still wear out then what?

 

[malcantry]

that ring gear can still be cut off.. the welding was only on the rivets/between the housing. certainly looks like my 03.5 diff did when i took it out..

being said. most upgraded differentials DO NOT come with ring gear. you must cut/drill out rivets and remove original ring gear in order to be able to use one such as MFactory..

but.. if you have any metal-work experience.. those welds will not hold up vs a skilled man with a grinder/cutoff wheel..

 

[Valk]

hmmm this seems like a pretty good time to ask... but my gearsets had some cuts in them when i had it all appart.. they look like they were machined into the gear teeth not chipped from debris. ive been chasing a off throttle ticking sound inside my trans and i figured it was a grenaded limited slip plate or bearing or somthing. before i had the trans open, it was present at all transmission rotating instances. after changing the input shaft bearings it was only present off throttle.. i dont think chips in the gears would cause a noise and a bad bearing would be present anytime the gears are in motion, but only on decel or coast?
Im thinking broken lsd... but im not a mechanic.

its coming out again toward end of summer for a new dif cause i know the lsd doesnt work anymore. maybe ill take more high res pics.

good to know i wont be in for a major job cutting out the rivots though!

 

[malcantry]

the gears can/will be machined with a slit through the middle, generally a worm gear not a straight gear,.. worms have alternating/moving constant contact with gear/gear as where vertical/straight gears actually CREATE contact between each other from tooth to tooth and creates a pounding/hammering effect (although not noticeable unless you have the harmonic/vibration analysis tools..

as per WHY.. the oil needs somewhere to go.. oil is non-compressible and while these wormgears are always under CONSTANT contact, this creates cavities of ever decreasing spaces,.. thats how a roots/screw supercharger works.. archimetes screw. large gaps compounded down to small gaps with any medium in-between will compound that medium.. ofc air is compressible so you get positive displacement with a SCharger. oil is not compressible, hence why pistons/hydraulics work.. close a space (piston) and the oil is forced through its easiest way out.. even if it means moving something 1,000,000,000 pounds. so long as the cylinder can hold the oil pressure..

those cuts allow pressure relief and debris from being compressed, but still allow the necessary oil to be involved for lubrication ability

just make sure your magnet at the bottom of your trans isnt massing bits of something.. all the metal will get washed down and collected by the mag.

the rivets on mine were 1/2 easy. some were just drillable.. but the others started spinning once i got the drill into it.. had to tac-weld to continue drilling. grinders work just as well but take maybe just a bit longer/concentration

sry for long reply lol

 

[Valk]

totally makes sense. the magnet collected most of the damaged bearing for me but i wonder if some of the metal came from the dif plate blowing. ah well. my gear sets and synchros came out of it unscathed so i count myself lucky. 135km and they looked brand new.
mfactory dif, 5th gear plate and i should be good for a bunch of kms. if not several motors lol.