Dismantling T2 - word of warning to you all!!!
Turbo Mini Forums

Got a cheap T2 that needed reconditioning the other day, and started to take it apart last night for a good inspection. It was all coming apart reasonably, bolts were a bit tight but to be expected with the temps that these things run at, the turbine housing came off okay, which then brought me to undoing the nut on the end of the shaft in front of the compressor wheel so I could withdraw the turbine wheel and shaft out the back. I clamped the boss on the end of the turbine wheel, and started to undo the 12 point nut, and BINGO IT SHEARED THE SHAFT!!!

Just thought i'd mention it in case anyone else is considering dismantling their turbo. I wasn't too bothered as I was only going to use the casings with no blades in for when I run the engine in (sometime in the distant future probably!!)

cheers

dan

Yup somtimes they do that, hence why a recon turbo from turbotechnics isn't cheap!

alex

AlexF

Definitely not cheap thats for sure, I remember when I used to have my 5 turbo I was thinking about a new turbo for some extra boost, and they are definitely expensive even for standard.

This turbo also had a quite large crack in the turbine housing running between the exhaust passage and wastegate, i've heard that this is quite common on the t2's.

I guess that the casings aren't easy to repair either probably leading to the already mentioned expensive re-cons!!

Edited by dan on 3rd Feb, 2004.

Ive also heard that casing cracks on T2's are very common. Especially where the wastegate seals onto the casting. Not run mine with the T2 yet so havent found out if it makes any difference. Pretty sure the wastegate doesnt seal very well anyway!

they all crack....

and cost a fortune to renew... about an extra ?100 on a rebuild.

Alex

AlexF

Bit of a design flaw i think!

The turbo ive got is apparently nearly new and thats cracked.

Hi,
Dan, do you mean that when you tried to undo the nut the shaft broked??
for info in which sens did you tried to undo the nut, clockwise or unclockwise?
I dismantled a certain numbers of T2's and all nuts came of easily,about the craks, some are not that bad, and some are really make a leak, about the craks, you'll can inspect the M numbers on the turbine hsg, it will inform you of the grade of metal used, there is M2 , M3, and M4 , this mean the importance of manganese in the mix, M4 are the bests.

fab

Hello there Fab, I undid the nut on the shaft in the normal anti-clockwise fashion. Is this wrong, are they left-hand threads on the shafts.

I'll have to have a look into the numbers on the housing, i'm at the work at the minute

cheers

You would feel silly if it was a left hand thread!

Cant say anything, i snapped a tie-rod end on an adjustable engine steady trying to do the same!

Its a steep learning curve, as long as its not too expensive then thats the main thing!

yes , Dan, it is an unbolt clockwise thread , or as you saying a left hand threads on the shaft.
do you need an other shaft and wheel (I've got one or two ) ?
As said Ian , the only ones who are not making errors are the one who didn't tried anyting ( my first error was to mount my 1100 zzr rod end in the wrong side, imagine what this produced....)
fab

Oh well, at least I now know as do a few others. Thanks for the offer of a spare shaft fab, but I think i will re-assemble the casings and blank of the centre piece of the turbo and use when I run the engine in.

Fab after seeing exactly how the turbo are assembled, have you looked into sizing some roller bearings instead of the plain bearings for the turbo???

cheers

dan

Sorry dan ,
It is quasy impossible to make an home BB conversion, it is better to look at factory BB turbo's as on some silvia's and other japanese cars,the problem is that they are T25's and can't flow enough before 4000 rpm's for a 1275 , ( generally called surge line or stall),
this said a t2 from a gt turbo , is ok for high boost and high revs for the mini, the gt turbo can sort about 190 bhp, before needing an hybrid turbo, so you can use in peace the T2 , it will also boost from very low rpm's and have quasi no lag.

fab

Edited by fab on 5th Feb, 2004.