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Astro/Safari Towing

nichunichu Member Posts: 2
edited July 2014 in Chevrolet
Does anyone know what would cause this issue: When I press my towing mode button on my shifter knob, when the car shifts from 1st to 2nd, it makes a loud thud sound. Again I dont know exactly which gear it is shifting in. But it only makes this sound when the tow button is enabled. With the tow mode off, the car shifts just fine?

Any help?


  • 1998lincoln1998lincoln Member Posts: 108
  • spike99spike99 Member Posts: 239

    Perhaps its a wording thing in the initilal post. Unknown to some. this "Tow/Haul" button should only be pressed (in or taken out) before vehicle is taken out of "P" gear. It should NOT be pressed in/out when driving down the road.


    The tow/haul button forces the vehicle's transmission to rev higher before shifting into its next available grear. Many say this feature "raises its shift points". If wondering, having a higher reving engine before shifting is a good thing (especially when vehicle is under load stress). Higher engine revs means less stress on the transmission. And, less "stress heat" being created by the transmission. Low RPM shift points create huge amount of internal heat. Thus, why many "tow capable" GM vehicles have tow/haul button feature as their minimum build.

    If one's transmission becomes "worn out" (re: high mileage or too much load stress during its many years), the transmission's "shifting" mechanism becomes loose (re: out of factory specs). Thus, rougher feeling when shifting up each gear. And when using the Tow/Haul feature, the engine is reving higher then normal shift points. Unfortunately, higher reving "shifting" transmissions don't like worn out gears.. Thus, why your vehicle shifts ok in normal mode but makes ugly "weird" sounds when in Tow/Haul mode.

    Long post short.... The vehicle's transmission needs a re-build. Thus, replacing worn out inner parts with new parts. And, these new parts are better then factory GM specs. As a "short term" solution, I'd replace transmission ATF, its under pan filter and install new Dexron ATF. Add some Lucas Transmission fix additive as well. re: http://lucasoil.hodgsoncorp.com/slipping_transmission.htm This "liquid fix" might resolve some "weird" transmission sounds and behavior. Especially if you plan to sell your van (and try to get top dollar for it). But for long term resolution (if you plan to keep your van for many more years), get your van's transmission re-built. Many specialized transmission shops will provide a rebuild estimate (using standard rebuild kits). Do shop around because rebuild prices do vary. If wondering, my previous van's transmission was rebuilt for $1,100. Afterwards, it ran better then factory. Glad I got its transmission rebuilt.

    Also... Do install an Aux LPD Transmission cooler on your van as well. Go with LPD design for towing $5,000+ lbs trailers. The 460LE transmissions do NOT like heat (even only used for soccer parent driving conditions). If you don't already have one, do install a HD Aux cooler. For example: http://www.transmissioncoolers.us/Merchant2/merchant.mvc?Screen=PROD&Product_Cod- - - e=1679&Category_Code=hayden-transaver-cooler&Product_Count=3
    Note: My local transmission specialist recommends "over sized" LPD coolers for all GM vehicles. Especially for the 460LE transmisison (found in Astro/Safari vans) - that cannot handle high amounts of "stress heat" & reginal weather heat.

    Hope this helps...

  • spike99spike99 Member Posts: 239
    Just want to emphasis....

    If your van tows / hauls 3,000+ lbs and/or you live in hot summer climate, I'd install the # LPD4590 tranny cooler. Its next size larger (then my prevous post) and can take "the heat" much better then its slightly smaller size cooler. For more details, surf:

    http://www.transmissioncoolers.us/Merchant2/merchant.mvc?Screen=PROD&Product_Cod- e=4590&Category_Code=trucool-coolers-hd&Product_Count=2

    Hope this helps as well...

  • hyper2hyper2 Member Posts: 2
    Hi, I have a 2001 Safari and I noticed that there is a taped wiring harness in the jack compartment just under the jack. After I unwrapped the tape I noticed that there are the normal left, right, lights, and ground wires. There also seems to be a few other heavier gauges wires. My question is would these wires possible be used for an electric brake set up?

    I have a complete electric brake setup from my Astro and I thought that It would save some time and labor if I did not have to run it from the front to back in the Safari.

    Thanks for any input, John
  • spike99spike99 Member Posts: 239

    I used to have an 2001 AWD Safari and installed a Class III hitch and Brake Controller within it as well. During my DYI wiring purchase investigation, I could NOT find any special order connectors for my Brake Controller to Astro/Safari "under dash" connector. My local RV dealer also stated that a brake controller for my specific van needed to me "manually" spliced in. Thus, I ended up installing a double insulated 2 x 10 Guage wire - from under dash Brake Controller to rear of vehicle (under the vehicle). re: http://www.etrailer.com/p-10-2-1/Jacketed-2-Wire-10-Gauge-Brake-Wire---per-Foot.- html If wondering, I purchased this special wire from my local RV Dealer (which was reasonably priced).

    Hope this helps...

  • hyper2hyper2 Member Posts: 2
    To spike99, Thanks for the input. I think that you are quite right and I will proceed to wire my harness from my Astrovan into the Safari. I have purchased a new Prodigy controller to replace the unit that I had as I have been told that it is one of the best out there.

  • spike99spike99 Member Posts: 239
    edited March 2010
    For my previous Safari (which is a sister vehicle of the Astro), I performed the following "towing" upgrades:

    - Installed Class III hitch. Also ensured the Class III was a square tube design - that can also accept a Weight Distribution system. Some of the class III hitches won't accept a WD System. Thus, do pick wisely. Unfortunately, Class III his is the largest hitch that can be installed on this van. Think I had a Hidden Hitch on my previous van. re: http://www.hiddenhitch.com/fitguides/details.asp?ProdID=87516

    - Installed Timbrens SES units in the rear. If wondering, Timbrens replace the factory bump stops. They are like air bags without pressurized air inside them. Very "low cost" and very "easy to install" upgrade. For more details on this "install it / lease it" suspension upgrade solution, surf: http://www.anythingtruck.com/susp_timbren.html

    Note: I love this product so much, I installed SES units on my buddies AWD Astro van and my wife's current GM mini-van. Well worth installing - even for non-towing vehicles.

    - Installed Large Size Aux LPD Design ATF cooler. My local mechanic says Astro/Safari vans run "hot". Even non-towing GM vans need aux cooler. Thus, focus on Hayden model 678 or the larger 679 design. For my van, I installed Hayden 678 LPD (Low Pressure Drop design) and it worked great. For more details, surf: http://www.summitracing.com/parts/HDA-678/

    - Installed Husky Excursion Brake Controller. To me, the Astro/Safari van factory brakes are very poor. Especially with onboard cargo &/or lots of passengers. Any trailer over 2,000 lbs behind this van design needs its own brakes. I'm sure your Prodigy brake controller will work great as well.

    Hope these other items help as well....

This discussion has been closed.