aju41046

I got two of the chra bolts loose but the wrench just keeps slipping on the other two and it’s starting to round them off. My wrenches have dents in them from the bolts rounding off. What do I do? I’m afraid to keep trying because if it gets much worse then they won’t come out...

jiinxy

They can be a mother.... you might need a damaged bolt wrench. Might need to use heat to get them to loosen up. Might break them and have to drill/tap the holes.

Gee Emm

"Wrench" means ... ? Sounds like an open wrench, best to use sockets or ring spanners if they'll fit. If necessary, cut/bend to suit. And don't use cheapies, it's false economy. Try some penetrating oil, and use heat. But first make sure your tools are up to the job.

deezums

iTrader: (3)

If your wrenches are getting dented from hex heads you need to invest in new wrenches.

Seriously, not even the cheap **** from harbor freight is that soft. Only place I've seen literal garbage like that is the cheap *** blowmold home tool sets, which are beyond useless.

aju41046

Wrench is Bluepoint Snap-on. No room for sockets

shuiend

iTrader: (24)

You need a Yellow MAP gas bottle and lots of heat on those bolts.

aju41046

I don't have any sort of torch or stuff like that, but I've got a friend who has one that I can probably borrow. I'll soak it for a couple days with penetrating lube and chuck it in the freezer the night before. My worry is again if I can't get it off then I'm going to end up rounding the bolts off. So let's prepare for plan B:

Say I do round the two remaining ones off, If I cut them off how does that work? Cut off the heads and then will the CHRA then be free from the turbine housing (with some coaxing)? The other two bolts won't completely come out bc they hit the CHRA before you can fully unthread them. This leads me to believe that the turbine housing will still be stuck (by a few threads on the two good bolts) to the CHRA even if I cut the two bolts off. So where do I go from there? If I cut the bolts off then I'm planning on welding a nut on to the remaining studs (assuming the CHRA and turbine housing will separate), and then I can extract the rest of the cut bolt out. I suppose I could just cut all 4 bolts off and then there would be no issue with getting the CHRA and turbine housing separated, I'm going to need at least two new bolts anyways...

I appreciate any thought or suggestions, I like to have a plan before I start something!

Gee Emm

How much effort is this worth? I have no idea what an sr turbo is, or why you would put one on an MX. Presumably this is something you picked up used, perhaps it came off another car of yours, else it would have come apart more readily. So is this particular turbo worth all this grief you are getting? Maybe it is trying to tell you something?

boileralum

iTrader: (8)

SR usually means SR20DET, aka Silvia turbo (t25), they are extremely popular on this board, I am kind of surprised you aren’t aware of them (not a poke at you, just genuine surprise).

To the OP, you have to use a closed wrench on those (and pretty much should use one any time you can be an open ended wrench)

aju41046

SR20 T25s are popular turbos for miatas. Very similar to GT2554, but the SRs are journal bearing instead of ball bearing, For a fraction of the cost, I'm choosing my SR turbo over a new 2554. The reason these turbos require some struggling to fit a miata is that the turbo must be clocked to be properly aligned for a miata setup. The bolts have been through thousands of heat cycles, and most used turbos have never had the bolts cracked loose since the turbo was manufactured.

Frofro97

Good luck, mine were a pain in the *** to remove, I destroyed most of them.
put the whole turbo in the oven, get it nice and hot, then oil and try to undo the bolts.
the oven trick also works great for separating the exhaust housing from the CHRA (that and hitting it with a big soft face hammer)

when reassembling I shifted the holding washers, so that the split part is under the most difficult spots.

aju41046

Good idea Frofro.

I was a dumbass and went hunting and found a wrench thin enough to get the box end on one of the bolts and got it loose! That still leaves one stuck on there though. Box end is impossible, I’d need to sand it down to a few mms to be able to fit and I don’t think that’s the best idea. I’m hoping thermal physics will help get the last one off. Tried just fitting an open end on it last night and it was super loose on there, I think the bolt is mostly done in.

curly

iTrader: (25)

Bash turbine housing with hammer. It’ll rotate. Get closed end wrench in there.

rleete

iTrader: (21)

Vice grips and a torch. Bernzomatic torch kits are cheap, and will last forever.

aju41046

The turbine housing will rotate even with a bolt still fully threaded in? I thought the CHRA was bolted to the turbine housing through those four bolts? I’ll look at a diagram or disassembly video tonight

curly

iTrader: (25)

It’s one tiny bolt. Don’t use a tiny hammer.

Frofro97

The Chra is clamped into the exhaust housing it will in theory rotate even fully clamped, but would need a lot of force ,probably enough to break things.
If you are hitting things with a hammer, Id use a cold chisel, or center punch, and try to hammer the edge of the bolt head to get it rotating lose

Gee Emm

I have been educated! Thank you all!

/thread drift

aju41046

I think I'll save bashing it with a hammer as a last resort...

dleavitt

iTrader: (1)

You really should reconsider. Not because I think it will help you clock the turbo (I don't have any direct personal experience in these matters), but because bashing things with a hammer is very therapeutic.