What did you do to your NNBS GMT900 Tahoe/Yukon Today?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
6,412
Reaction score
15,886
Location
Richmond, VA
What did I do to my GMT900 today (well on Tuesday)... Got it towed away for a transmission rebuild. I missed the call from the shop today, but it seems the pump and torque converter are the cause of failure, but they didn't say where all the fluid was pouring out. I had a circle d converter in it, so I'm anxious to see what happened to it when I speak to them tomorrow. Estimate is looking like $7k plus, but this is considering the HD parts going back inside it.
Bummer. I’ll also be interested to hear what you find with the converter.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,163
Reaction score
39,197
Location
Stockton, Ca.
What did I do to my GMT900 today (well on Tuesday)... Got it towed away for a transmission rebuild. I missed the call from the shop today, but it seems the pump and torque converter are the cause of failure, but they didn't say where all the fluid was pouring out. I had a circle d converter in it, so I'm anxious to see what happened to it when I speak to them tomorrow. Estimate is looking like $7k plus, but this is considering the HD parts going back inside it.
is that the beverly hills shop? holy crap, had mine rebuilt for 500hp and all the fixes it was $4000 w/100k 3yr warranty, maybe I got good deal.....
I even made it perfeclty clear I intended to boost it, so I wanted it built right
 

the_tool_man

Full Access Member
Joined
Oct 15, 2018
Posts
750
Reaction score
1,713
Location
Upstate South Carolina
is that the beverly hills shop? holy crap, had mine rebuilt for 500hp and all the fixes it was $4000 w/100k 3yr warranty, maybe I got good deal.....
I even made it perfeclty clear I intended to boost it, so I wanted it built right
When my OEM stock (BB tuned) tranny failed earlier this year, I was in the middle of moving and needed my Yukon back ASAP. My only viable option was to install a GM-built HD transmission, as the local dealer had one in stock and couldn't get a non-HD one for weeks. That was $4200. By the time I paid labor, replaced the radiator (for trans cooler) and cooler lines, and change the fluid in the TC and diffs, it was about $6k total.
 

m1dn

Full Access Member
Joined
Jun 15, 2022
Posts
178
Reaction score
316
Truck has been running rough on cold start for about a minute or less for a while now, didn’t pay much attention to it.

Now yesterday it got rougher and didn’t go away, then got bad in drive around 1-1.2k rpm.
Finally engine light popped up for few seconds and i was able to read it as cylinder 2 misfire.

Swapped wires, still cylinder 2.
Spark plugs are less than a year old, maybe 10k miles tops, NGK TR5.
Took out the plug and it looked fine, clean!

Replaced single plug with NGK TR5IX, runs smooth again and no rough idle on cold.
Never seen a single plug go bad!

Also got a top engine cleaner just in case, might run it over the weekend
 

the_tool_man

Full Access Member
Joined
Oct 15, 2018
Posts
750
Reaction score
1,713
Location
Upstate South Carolina
Truck has been running rough on cold start for about a minute or less for a while now, didn’t pay much attention to it.

Now yesterday it got rougher and didn’t go away, then got bad in drive around 1-1.2k rpm.
Finally engine light popped up for few seconds and i was able to read it as cylinder 2 misfire.

Swapped wires, still cylinder 2.
Spark plugs are less than a year old, maybe 10k miles tops, NGK TR5.
Took out the plug and it looked fine, clean!

Replaced single plug with NGK TR5IX, runs smooth again and no rough idle on cold.
Never seen a single plug go bad!

Also got a top engine cleaner just in case, might run it over the weekend
Man, I'd be sweating if that had happened to me. I read over and over about a misfire code being indicative of a lifter failure! I'm glad it was just a plug. Why NGK and not ACDelco? I'm asking because I just swapped mine and went with OEM.
 

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
6,412
Reaction score
15,886
Location
Richmond, VA
Truck has been running rough on cold start for about a minute or less for a while now, didn’t pay much attention to it.

Now yesterday it got rougher and didn’t go away, then got bad in drive around 1-1.2k rpm.
Finally engine light popped up for few seconds and i was able to read it as cylinder 2 misfire.

Swapped wires, still cylinder 2.
Spark plugs are less than a year old, maybe 10k miles tops, NGK TR5.
Took out the plug and it looked fine, clean!

Replaced single plug with NGK TR5IX, runs smooth again and no rough idle on cold.
Never seen a single plug go bad!

Also got a top engine cleaner just in case, might run it over the weekend
It's possible that the plug got dropped somewhere along the way, which can lead to micro-cracks in the insulator. When that happens, they will start misfiring eventually.
 

m1dn

Full Access Member
Joined
Jun 15, 2022
Posts
178
Reaction score
316
Man, I'd be sweating if that had happened to me. I read over and over about a misfire code being indicative of a lifter failure! I'm glad it was just a plug. Why NGK and not ACDelco? I'm asking because I just swapped mine and went with OEM.
No OEM in Canadian Tire, didn’t want to wait tbh
 

mikeyss

Full Access Member
Joined
Nov 11, 2011
Posts
1,700
Reaction score
3,243
Location
Longmont, Colorado.
is that the beverly hills shop? holy crap, had mine rebuilt for 500hp and all the fixes it was $4000 w/100k 3yr warranty, maybe I got good deal.....
I even made it perfeclty clear I intended to boost it, so I wanted it built right
How long ago was this? In today's economy, everything seems to cost way more, lol

I feel the pricing for mine is on point, I am getting a billet reinforced rear planet, billet 4-5-6 hub, 6 pinion input planet, new billet converter, new steels and clutches, brand new bell housing and pump, etc.
 

Forum statistics

Threads
132,253
Posts
1,864,800
Members
96,804
Latest member
Bigjohnny

Latest posts

Top