Mods/unmods to my 95/99 6.5's? Need advice.

[WarWagon]

Pins A&B for paperclip code reading are generally the passenger side toward the back of the connector. If you look on the firewall side of the connector they are labeled in raised small black letters. NVW beat me to it...

http://www.thetruckstop.us/forum/threads/a-little-help-here.2657/#post-50700

Your tow capacity, suggested 5000 lbs trailer, is less than the hitch rating. Check your manual and some other sources to be sure. You have a 1500 where most of us have a 2500 that can handle more.

http://trailers.com/tow-capacity/1995_Chevrolet_GMC_Suburban_K1500_(4WD)_1390.html

Transmission and tune:
The tune allows you to take advantage of the bigger turbo and controls the transmission etc. Some tuners allow you to keep the Torque converter clutch locked when you lift off the throttle. Don't do this. You will notice when you coast (TCC unlocks) and then add throttle the engine RPM will flair up and then the TCC locks bringing the RPM back down. This factory behavior is easier on the transmission. A high stall converter really shows the RPM flair during this. Lock on lift means the TCC stays locked up when you lift off the throttle. So when the engine goes from no power to some power the "wham" is transferred to the transmission rather than slipped away in an unlocked converter. I have not done it, but, word is this shock can snap the input shaft. Further the overrun clutches used for compression braking only are weak and easily overpowered if the TCC is locked. I have burned this clutch set up 3 times.

Turbo's:
Lots out there. Few years ago one was the devil for even suggesting a different turbo rather than the turbomaster on the GM Krap. That other place forum is very high on some of our s#it lists over their ignorant turbo attitude. Not finding the proper turbo info to solve GM's OEM problem cost me a lot of money in wasted fuel as I was going 550 miles a day at 7MPG when I could have gotten 10+ MPG. Costing me money like that over willful ignorance just to s#it on a non-vendor raised their ranking...

Done the best I can to post results. So have some other members who have experimented with other turbo's, spool valves, precups etc.

The one thing to remember with this engine is it needs to rev up so it has the HP to back up the TQ it makes. The OEM GMx turbo chokes at high RPM.

Boost vs. HP/TQ. Here is 15 psi vs 24 psi making the same power. Why? The back pressure on the HX40II is higher to get 24 PSI of boost. So hotter intake air at 24 PSI and higher back pressure = same power as the larger turbo. Note most larger turbo's don't light off (provide boost) until 2000 RPM. The HX40II starts to fade out before redline where the larger ATT will pull like a freight train past red line. The GMx will spool up off the starter. But it chokes over 2200 RPM. This was the trade off GM made a light 1/2 ton setup dropped into a big vehicle and expected to work just fine loaded.
http://www.thetruckstop.us/forum/threads/att-run-vs-hx40ii.38950/

 

[WarWagon]

Thanks guys for the links I am going to take my time later tonight when I have time and read up with my notebook open.

Now here are the pictures of the rear driver side engine to see if the original glow plug controller is there.

After reading codes take apart the ground indicated and make sure it's spotless and the wires and connectors are in "perfect" shape.

I see where they cut the ECM glow plug control wires and put the manual switch to control the GP controller. You will need to match the wire colors they cut and repair them.

 

[JayTheCPA]

Your tow capacity, suggested 5000 lbs trailer, is less than the hitch rating. Check your manual and some other sources to be sure. You have a 1500 where most of us have a 2500 that can handle more.

Even though the body has the 1500 marking, IIRC an option was to have a 3/4 ton rigging, so it might actually have better than a 1/2 ton suspension. Or perhaps this was detailed in one of the other threads and I missed it. Definitely agree that the RPO code and / or door sticker will show what suspension is in the truck and then figure out towing capacity from there.

 

[WarWagon]

GCVWR Gross Combined Vehicle Weight Rating on the door minus the CAT Scale weight of the Suburban with a full fuel tank is how much he can tow. Some of these numbers are due to spring selection, tire ratings, brake limits etc. Thus before buying a trailer he needs to triple check the rating of the vehicle in front of him as options change the ratings.

Agreed that 1500/2500/3500 is just political marketing where a 1 ton can be labeled a 2500 for reduced license plate cost. 1500 vs. 2500 may be LD, light duty, vs. HD emissions . LD would have an EGR for example.

8 Lug is generally the 3/4 ton arena.

 

[btfarm]

Now the PO Dave AKA spdgofast...

Light bulb goes on in my head... You might spend time reading anything he posted in the past and find an interesting fact or 3

 

[aLpHaSuRf]

As we established earlier in this thread my truck has a non EGR intake and manifold. The door sticker is there but no writing can be seen would the glove box sticker tell me more! The brakes actually kick A$$ on her a lot different then my two 5.7 suburbans and 3 those I now own have owned.

 

[aLpHaSuRf]

Here is a pic.
The hitch on my suburban

 

[aLpHaSuRf]

Pic of sticker in glove box. Edited to add my vin starts with a #1 it's a USA truck not Mexico.

 

[JayTheCPA]

Here is a pic.
The hitch on my suburban

That is the hitch receiver's capacity, not the truck's.

And just for clarification, the higher values are for weight distribution hitches and not a simple ball.

Pic of sticker in glove box.

Somewhere in the list of RPO codes is the answer in terms of the suspension package.


If there is a sticker on the door pillar or door, it will have the values in numbers. Will also clearly show the GCVWR.

 

[aLpHaSuRf]

If there is a sticker on the door pillar or door, it will have the values in numbers. Will also clearly show the GCVWR.

Door sticker is there but no visible writing at all just a blank white sticker.

 

[Burning oil]

This is a really good informative thread.
You can swap the HX turbo to the 95 no problem, but you would want a tune also. 96 and newer is obdII and 94-95 is obdI so you could not swap the tune/ECM to the 95.

Check out my web site when you get a minute. Click logo below
VVVV

 

[JayTheCPA]

If there is a sticker on the door pillar or door, it will have the values in numbers. Will also clearly show the GCVWR.

Door sticker is there but no visible writing at all just a blank white sticker.

Actually, possibly my bad about the door sticker as mine does not have the suspension rating or the CGVWR. If you want to make it easy on yourself, go to CompNine<dot> and pay just a few $ to get plane-English translation of your RPO codes from the as-built database. CompNine will list out the RPO codes along with the meaning.

 

[JMJNet]

There is a whole bundle of wires with electrical tape near the GP controller area, that is not stock. That is probably where you can trace the GP override from the PO.

I would not worry about the fuel filter if it is not leaking as WW point out in the pic.

 

[snarl95]

AG9 252 P AFT R ADJUSTER FRT ST POWER, 6 WAY 980213 E 1 E A
AJ1 352 P GOT R WINDOW TINTED DEEP, ALL EXCEPT W/S AND DRS 910404 E T E A
AS3 678 P SEAT RR SUBURBAN/UTILITY 20514 E T E A
AT5 716 P SEAT RR CTR, FLDG 901022 E E E A
AU0 747 P LCE R LOCK CONTROL, ENTRY REMOTE ENTRY 970124 E E E A
AU3 750 P LOCK CONTROL SIDE DR, ELEC 910213 E E E A
AU6 753 P LOCK CONTROL END GATE WINDOW, REM CONT ELEC RELEASE 910607 E E E A
AXP 844 P VIN IDENT POSITION, MULTI-PURPOSE VEHICLE 890110 P T T A
A31 1072 P WINDOW POWER OPERATED, ALL DOORS 970310 E F E A
A95 1292 P STS M SEAT FRT BKT, HIGH BACK, DRIVER & PASS RECL 980623 E E E A
B33 2370 P FMR R COVERING REAR FLOOR MATS, AUX 880729 E E E A
B37 2374 P COVERING FLOOR MAT, FRT & RR, AUX 970508 E E E A
B71 2512 P WHM R MOLDING WHL OPENING COLORED 890530 E 4 E A
B85 2552 P BSM R MOLDING B/S EXTERIOR, BRIGHT 911205 E T E A
C25 3632 P WIPER SYSTEM RR WINDOW, INTERMITTENT 980908 E E E A
C36 3669 P HEATER AUXILIARY 830101 E E E A
C49 3708 P DEF R DEFOGGER RR WINDOW, ELECTRIC 840403 E E E A
C51 3736 P DEFLECTOR RR WINDOW, AIR 841009 E E E A
C60 3771 P HTR M HVAC SYSTEM AIR CONDITIONER FRT, MAN CONTROLS 980126 E E E A
C69 3780 P HVAC SYSTEM RR AIR CONDITIONER 900208 E E E A
DK6 4281 P CRS R CONSOLE ROOF INTERIOR 910606 E 1 E A
D48 5003 P MIR M MIRROR O/S LH & RH, REMOTE CONTROL, ELECTRIC, COLOR. 980422 E 1 E A
D55 5036 P CSL R CONSOLE FRT COMPT, FLOOR 880713 E E E A
E55 6332 P BDS M BODY EQUIPMENT END GATE 890405 E T E A
FE9 6660 P CER R CERTIFICATION EMISSION, FEDERAL 930430 M E E A
FF6 6693 P ARM R ARM LH TORS BAR SPRING ADJ (E) 970507 E T E A
FF7 6694 P ARR R ARM RH TORS BAR SPRING ADJ (F) 970507 E T E A
GU6 8529 P RAX M AXLE REAR 3.42 RATIO 830101 E E E A
G80 9027 P AXLE POSITRACTION LIMITED SLIP 910326 E T E A
JAN 11678 P PLT R PLANT CODE JANESVILLE, WI, USA 970425 E T E A
JD7 11806 P BRK M BRAKE HYD POWER, DISC/DRUM, 8,400 LBS 980623 E 1 E A
KNP 13444 P COOLING SYSTEM TRANS, HD 913 E T E A
K34 14035 P CRUISE CONTROL AUTOMATIC, ELECTRONIC 840410 E F E A
K68 14147 P GEN M GENERATOR 105 AMP 840710 E 2 E A
L65 15440 P ENG M ENGINE DIESEL, 8 CYL, 6.5L, TURBO, HO 980601 E 1 E A
MT1 16264 P TRN M TRANSMISSION AUTO 4 SPD, HMD, 4L80-E 970424 E T E A
NA5 16880 P EMS M EMISSION SYSTEM FEDERAL, TIER 0 931216 E E E A
NP5 17420 P SWL M STEERING WHEEL LEATHER WRAPPED 830101 E E E A
NY1 17740 P SHIELD FUEL TANK 830101 E E E A
NZZ 17774 P SALES PACKAGE SKID PLATE, "OFF ROAD" SPOT 980623 E T E A
N33 17922 P SCL R STEERING COLUMN TILT TYPE 830101 E E E A
PO6
QIZ 21050 P TIR M TIRE ALL LT245/75R16/E BW R/PE ST TL ALS 120Q 970626 E T E A
R5B 23150 P TBA R TIRE BRAND ALL DUNLOP 980211 E 0 E A
R9B 23294 P CONTROL SALES ITEM NO. 77 880217 P E E A
SLL 23736 P SPC R SALES PROCESSING SOLD ORDERS 10209 P T T A
TFE 24809 P SALES INCENTIVE COMMITMENT PLUS 981204 P T E A
UP0 26487 P RDO M RADIO AM/FM STEREO, SEEK/SCAN, AUTO REV MUSIC SEARCH CASS, CD, AUTO TONE, CLOCK, ETR 980619 E 4 E A
UQ3 26526 P SPR M SPEAKER SYSTEM PERFORMANCE ENHANCED AUDIO 850121 E 1 E A
VK3 27606 P LPF R LICENSE PLATE FRONT FRT MOUNTING PKG 951108 E E E A
VR4 27859 P TRL R TRAILER HITCH WEIGHT DISTRIBUTING PLATFORM 830101 E E E A
VXS 28063 P VEHICLE COMPLETE 891114 E T T A
VZZ
V27 28258 P GUARDS BUMPER, FRT 980622 E T E A
V54 28363 P LUG R LUGGAGE CARRIER ROOF, PAINTED 890417 E E E A
V73 28434 P VCS M VEHICLE STATEMENT USA/CANADA 970508 E E E A
XHH 30068 P FTR M TIRE FRONT LT245/75R16/E BW R/PE ST TL ALS 120Q 970626 E T E A
YD3 31242 P AXLE (BASE EQUIP) FOR SCHEDULING GVW PLATE 890503 P T T A
YD6 31245 P SPRING RR, BASE EQUIPMENT 970505 P 1 E A
YE9 31284 P CND R CONVENIENCE PKG COMFORT & DECOR LEVEL #3 890523 E T T A
YHH 31364 P RTR M TIRE REAR LT245/75R16/E BW R/PE ST TL ALS 120Q 970626 E T E A
ZHH 32660 P SPT R TIRE SPARE LT245/75R16/E BW R/PE ST TL ALS 120Q 970626 E T E A
ZP6 32973 P SALES PACKAGE COMBINATION - RR WINDOW WIPER/RR WINDOW DEFOGGER 910515 E T T A
ZQ2 33005 P SALES PACKAGE DRIVER CONVENIENCE 910517 M 1 E A
ZQ3 33006 P SALES PACKAGE DRIVER CONVENIENCE II 910515 P T T A
ZY1 33292 P CCC R COLOR COMBINATION SOLID 960806 E T E A
Z82 33653 P TPK R TRAILER PROVISIONS SPECIAL EQUIPMENT, H.D. 890807 E T T A
Z88 33659 P MAR M MARKET BRAND GMC 10507 E T E A
1SB 35642 P SPP R PACKAGE OPTION 02 880210 M 1 E A
1SZ 35666 P DISCOUNT OPTION PACKAGE 890410 P 1 E A
6GR 41706 P FLH M COMPONENT FRT LH COMPUTER SEL SUSP (6GR) 890116 E T E A
7GK 42995 P FRH M COMPONENT FRT RH COMPUTER SEL SUSP (7GK) 880602 E T E A
79D 44032 P TRM M TRIM COMBINATION CLOTH, RUBY RED (D) (96) 960118 E E E A
79I 47577 P CCM M INTERIOR TRIM RUBY RED (96) 960118 E E E A
96U 48041 P CCU M PRIMARY COLOR EXTERIOR, ULTRA SILVER MET (02) 20419 E T E A
96U 48150 P CCU M PRIMARY COLOR EXTERIOR, CAYENNE RED MET (02) 20419 E 1 E A
96U 49333 P CCU M PRIMARY COLOR EXTERIOR, EXTREME YELLOW MET (03) 601 E E E A
96U 49093 P CCU M PRIMARY COLOR EXTERIOR, ALPINE WHITE (02) 20419 E B E A
96U 49544 P CCU M PRIMARY COLOR EXTERIOR, BRIGHT WHITE (05) 20827 E 3 E A

There you go. If anybody wants the RPO's I'll e-mail the file to you.

 

[aLpHaSuRf]

Snarl95 thanks for the RPO codes. Does that tell me about my suspension and brakes? I saw brakes rated 8,400 lbs? Is that light duty or heavy duty

 

[JayTheCPA]

Agree that the brakes are likely 3/4 ton (JD7) which likely means the rear shoes are likely 3-1/2" wide (which is good); naturally check the actual size when you have the opportunity. In any event, when the time comes, move up to the 1 ton parts, proportioning valve, wheel cylinders (http://www.thetruckstop.us/forum/th...-and-94-99-dodge-2500-3500.44950/#post-513186) and add the 2" spacers to the rear wheels.

Not sure about the suspension as I'd expect to see something like RPO code C6P 'GVW RATING 8,600 LBS/3, 900 KG 8600 LB/3900 KG GVWR' were it a 3/4 ton. Given the 3.42 rear (GU6), I'd suspect the suspension is 1/2 ton.

The Burb has the trailering package (z82) and just check to see whether you have one or two coolers in front of the A/C condenser. If there is only one cooler, chances are it is for oil and you will want to add an aux tranny cooler.

If you still have the 105 Amp alternator (K68), this is going to need upgrading to at least the 140 Amp range for towing.


In any event, definitely a good platform to start with!

 

[handcannon]

GM did some rather crazy things with the Suburban brakes. With 8 lug axles you could easily have 2 1/2" or 3 1/2" drums. I have personally seen, in wrecking yards, 3/4 ton Subs with 3 1/2" rear brake drums and shoes and full float hubs, which are what you would normally see on 1 ton SRW pickups. I've also seen 3 1/2" drums on a semi-float rear end, but didn't see the size of the shoe.

However, you can't just go by the size of the drum that you see. Although I haven't seen this, I've read where some Subs got the 3 1/2" drums with the 2 1/2" shoes. In this situation I don't know if 3 1/2" shoes can be put in place of the 2 1/2" shoes, but it would be something to check out.

Whatever you do with your brakes make sure you upgrade the front brakes before the rear brakes. Upgrading the rear brakes first could easily upset the front/rear bias. You don't want the rears locking up before the fronts do their job.

Don

 

[tanman_2006]

Both trucks need a full 3 gauge pod, Exhaust, lift pump (and relay on the 95), and tunes to make the best of those turbos.

IMO, leave the HX 35 on the hoe. Use it for your DD and let that turbo push the little truck around and low rpms.

Get an A Team for the big burb and let it scream while towing the way it likes it. Don't waste your time or money swapping turbos when it would be best to just ponny up on the tow rig from the beginning.

I'd keep both but that's just me.

 

[jrsavoie]

When you do the dual lift pump relay upgrade, do not cut and splice. Do it like Leroy does, plug and play.

If you order Leroy's, you may have to ask for the prime feature. I'm not sure if he automatically adds the prime feature or not. IMHO the upgrade is almost a waste if you do not add the prime feature.

Also add a toggle switch while doing the upgrade. it is great for priming the filter and helps with diagnostics.

I do not care for a momentary switch. It ties your hands up

 

[GM Guy]

First off, how much money can you allocate for the project? Will we see your name in the obituary if you spend too much? Got any kids?


First off, since you dont tow much or at all right now, I would simmer down on any towing upgrades.

I would save money and spend it on reliability boosting upgrades.

If I was you, my immediate plan of action would be:

Keep the diesel tahoe, and the burb.
On both, inspect harmonic balancer and pulley, and oil cooler lines. address any leaks, get everything squared away on filter and fluid changes (fresh brake fluid, PS fluid, maybe trans, etc. hold off coolant change, it will be changed soon enough doing cooling upgrades. ) and any front end work needed.
Essentially get all basic maintenance squared away before upgrading, then start in on modifications.

tahoe plan:
1) Keep the turbo, and using car-part.com, find a junkyard to get the f code upper and lower intake to delete the EGR.
2) My personal opinion, (likely to be opposed. ) convert back to OEM GP controller. sounds like it needs new GPS too, AC Delco 60G or Bosch Duraterm.
3) new filter nut from Leroy, and get a new metal lid filter.

Suburban plan:
1) K47 airbox
2) Leroy's Lift pump relay kit.
3) start saving up for cooling system upgrades. The good thing is by waiting, you will be able to dive right in with Leroy's upcoming electromagnet engaged fan clutch and not waste any money on a viscous fan clutch.
You will need to go with the AC Delco 88894035 pump (OEM for a model year 2000 6.5L), your choice in fans, wither the OEM for 97+ 9 blade steel, or the poly Duramax fan.
4) also save up for towing/ performance upgrades, the A-Team turbo is a favorite, along with a Diamond Eye exhaust.


Having a multi-vehicle fleet is black hole for $, so spend wisely.